Final Fantasy Tactics/WMG

Ramza isn't entirely human.
One of the unique spells Ramza can learn via the 'hit by attack and survive' mechanic later in the game is Ultima. In a case of The Dev Team Thinks of Everything, the other two types of charachters that can learn this spell is Ultima Demons... and Alma. Who is Ramza's mother, again?
 * In the remake, Luso also gets it. Then again, Luso in FFT is a walking FFTA 2 teaser trailer, and his being a Ramza clone as far as abilites go, might be a way to indicate that Luso would be more like Ramza than like Marche.

Saint Ajora has been reincarnated more than once.
In both the Japanese FFXII Clan Primer and the Ultimania timeline Ajora is called a woman. Yet, Germonique's scriptures refer to him as a man, not to mention there was a portrait within the game's data that shows Ajora with a fairly manish face. Keep in mind that it's been established that reincarnation exists in Ivalice. So therefore, Ajora was born a woman at first, does her thing and possibly makes contact with Ultima, dies, is reborn as a guy and makes history. He/She is reincarnated again as Ramza's sister Alma but is defeated.

The events of Final Fantasy Tactics were a historical simulation of the real events.
Explains why you're in no hurry to finish the main quest. And why Ramza, or any other character, can get so ridiculously, unstoppably powerful.
 * 'Ramza' and 'Arazlam' are actually modern-day Ivalician Ren-Fair performers.
 * Assassin's Creed crossover! GO!

The Church's history of events is actually more correct than that of the Durai report.
Ramza was a murderer and a heretic, and Delita was the hero-king who brought Ivalice out of the Lion War. What, Olan didn't have his own agenda when writing the Durai Report?
 * Conversely, the traits of the characters were magnified and/or distorted.
 * Say, for example, Ramza wasn't a saint, though he may have helped save the world.
 * And neither was Dycedarg a regicidal, patricidal, scheming manipulative bastard, though he was an opportunistic ambitious man.
 * However, Cid was still a friggin' Badass.

Olan was more or less on the mark... except that he couldn't resist writing himself and his uncle Orlandu as more Badass than they really were.
(At least Orlandu really was a skilled warrior.) The whole rescue scenario makes a good deal more sense if Olan couldn't freeze enemies in time, after all...

The Durai Reports were written by Ramza
Ramza, the Beoulve Black Sheep and a "bastard" child (or at least the son of a concubine/second wife), shipped off to the Ivalice equivalent of boot camp, just happened to be the future king's best friend and the lynch-pin in saving Ivalice from demons trying to take over the church? Yeah, right. Olan was what Ramza was really like, changed into T.G. Cid's nephew because he hated his real-life family.

Delita's another one of Balbanes' sons.
Why else would Balbanes bend the rules to have Ramza's so-called "best friend" enrolled in the Academy? (Teta, however, is Delita's half-sister by the man their mother married to hide this fact.)
 * You must not leave out the possibility, though, that Balbanes knew his bloodline was unfit to rule. Knowing this, he would have gotten Delita into the academy because he saw Delita's indeed impressive ability to make a plan and come out on top.

Ramza is X returned

 * Germonique
 * "Ajora lives again, mortal-oh hell, not again."
 * Smack, Ajora hits the ground. "Ajora the mighty is getting sick of this shit. Stop getting reincarnated!"
 * Very vaguely suggested that Ramza is at least of some kind of bloodline that Ajora recognizes.
 * Cid, because Cid's so Badass he's been resurrected before his death.

Final Fantasy Tactics takes place after Final Fantasy XII, so the adventures during Final Fantasy Tactics Advance and Final Fantasy Tactics A2 were from time travel
If memory serves me correctly, Final Fantasy Tactics mentions somewhere that guns, airships, and some forms of magic were commonplace ages ago but are now ancient relics of the past. If you think about it, in the world of Final Fantasy XII, Advance, and A2, magic, guns, and airships were a part of daily life. It's possible that perhaps an extremely powerful magic wiped these out and most civilizations, which is why there are no moogles, vieras, bangaas, seeqs, nu mous, or grias in Final Fantasy Tactics. Marche also bears a resemblance to Ramza, so he could be his descendant. The Ivalice that Marche and Luso go to was at its prime, so the grimorie most likely made them go back in time. The order of the games would be FFXII > FFT > FFTA > FFTA2.
 * Or rather, {FFXII and Revenant Wings / FFTA adventures / FFTA2 adventures} > FFT adventures > Vagrant Story > FFTA framing device > FFTA2 framing device. There's also speculation that while FFTA2 is true time travel to the era of FFXII, the original FFTA took place in a fantasy version.
 * Gametrailers had a Final Fantasy Retrospective that confirms this, showing the map layouts of FFXII and FFT, specifically that FFT is to the west of FFXII. Historically and stylistically, FFXII could take place in the equivalent of the Roman Empire, whilst FFT is the Middle Ages. As for the tech decline, it seems the Airships in particular were fueled by magicite, and if this was all used up, and nethicite manufacturing was forgotten or deemed illegal due to accidental disasters or terrorist uses, they would stop working.
 * Gametrailers didn't really have their facts straight, but yes, this timeline is confirmed in the Ultimania. The patched together in-game maps from FFXII and FFT are wrong however; watch the prologue of FFXII again, and you can see there's a vast expanse of Ordalia in the way of that theory. The presence of Goug city in TA 2, however, probably indicates that (following the Cataclysm that screws up technology) the Ordallian half of Jylland becomes the region from FFT. So FFT takes place on the other side of the continent from FFXII, but in the same region as FFTA 2, though changed so much that it's mostly unrecognisable except insofar as it's a west-facing peninsula and has a city called Goug.

The ending was a result of Olan Durai "writing in" Ramza and company's death when they really survived and escaped Murond

 * Think about it. Ramza and company have just killed off Altima and they claw their way back up to the surface, alive and well. They've saved the world, but the world very decidedly wants to kill them. Everyone's at peace, pretty much. They could go ahead and continue the fight, or let everyone believe they've well and truly died. A little while after Ramza's funeral, Ramza drops off his accounting of the Zodiac Brave Story, which Olan adapts into the Durai Report, purposefully leaving out the portion where Ramza and everyone else survive.

The Scriptures of Germonique are themselves one big fat lie, and Simon's desire to propagate that big fat lie leads to a lot of chicanery.
Reading the Scriptures of Germonique, you get this bit of rambling from Simon about how they're entirely based in fact: "Although many spoke of their existence, none had ever set eyes upon these Scriptures of Germonique. Some might say they are fraudulent, written with the sole purpose of discrediting Saint Ajora. But I know this tome to be authentic."

"When I served as an inquisitor for the Church, many others in the Holy Office feared the existence of this work. And the same is no doubt true for the High Confessor. They were all fearful of these writings, for everything contained within them is fact."

However he never goes on to give any evidence that any of these claims made by Germonique, who was known to be a particularly sketchy and traitorous individual, have any semblance of truth in them. Germonique may just as well have had a vendetta against Ajora and wanted to wipe out his following, traitor that he apparently was. This would mean that the face-off with Ultima at the end of the game is largely the concoction of Orran's mushroom-addled imagination.


 * Alternatively, the Scriptures are a lie in that the story they tell is absolutely meaningless. The Scriptures, after all, were actually meant to contain the code to activate the portal in Orbonne, and are nothing more than elaborate Spy Speak.

When Delita was caught in Fort Zeakden's explosion, Teta's body crystallized shortly after and healed Delita.
Hence why Delita says Teta saved him.

On the other hand, since crystal are known for empowering others with the deceased's knowledge, Delita may very well have been privy to Teta's last memories. I rather doubt they were peaceful. Imagine if her last thoughts were, "I don't want to die." Or the realization that she's been betrayed by her adoptive family.

No wonder Delita has such a chip on his shoulder.

Ramza was due to star in a Harem Anime, bound to wind up like Tenchi or Sena, until the war erupted.
The man rescues women left, right, and center and even has a potential Unlucky Childhood Friend or Victorious Childhood Friend in Teta/Tietra. Note that, without the war and everybody in the country going stab-happy, every woman he rescues are people he could have reasonably been expected to meet over the course of his life anyway. He would have met Agrias while she was guarding Ovelia, met Izlude and Meliadoul through Vormav and Dycedarg associating with one another, and probably would have foiled an assassination attempt by Barinten, leading Rafa to fall in love with him in the process.

Damn. Now I want to see this.
 * I do too, the solution is fan fiction. Get crackin.
 * It appears someone did.

Orlandu is actually Sean Connery
That's why he's so broken.

Non-Lucavi magic doesn't exist (or is extremely rare) outside of gameplay.
Which explains why the zodiac stones are viewed as extremely powerful in-story despite the fact that they don't do very much that can't be replicated in gameplay. Reviving the dead is something that every White Mage worth their salt is able to do, and yet no one thinks to use a raise spell on Tietra, and Malak's revival via zodiac stone is seen as a miracle.
 * No, it's because there's a difference between the Revive spells bringing people back from near death, and the Zodiac Stones bringing someone back from actual death.
 * Revive spells are almost never mentioned in cutscenes, AFAIK. The closest I can think of is Ramza asking for a phoenix down, but that's not the same thing. Besides, the fact that revive spells work just fine for characters who just had their souls sucked out of them or were hit at point-blank with a fireball from the King of Dragons, it's hard to believe they'd just stop working for "mere" bullet or crossbow wounds, just because it's a cutscene. Hence why it's slightly more believable to think that the spells are just there for gameplay reasons and don't exist in-story.

Wiegraf is a Clueless Chick Magnet
And this is why, the two times you fight him in a group, he appears with a bunch of ladies.

Ramza Beoulve and his companions are the heroes of The Zodiac Brave Story, and, by symbolic extension, the real Messiah of Ivalice.
So, according to the ZBS, a power hungry king summoned demons to the world, and a hero gathered the 12 Zodiac stones and Braves to defeat the demon king. Now, what happens in The War of Lions? Any of a number of persons qualify for "Power Hungry King", but none better than Folmarv and the Glabados' leader. So they grab the Zodiac stones and, surprise! Summon demons into the world. Meanwhile, Ramza Beoulve and his companions gather the stones and ultimately pry them from the hands of demons to save the world.

Notably, Ramza and company exceed the 13 permissible, though it could be said that some of Ramza's followers aren't equal to others.

So say we count only the 12 most important aside from Ramza. Namely, Agrias, Cidolfas, Meliadoul, Rapha, Marach, Mustadio, Beowulf, Reis, Alicia, Lavian, and Ladd. You can dispute the canonicity of say, Cloud, Balthier, and Luso, so we discount them from the theory. Boco, Byblos, and Construct 8 are unlikely for being of the non-human variety. Now, for those keeping count, we've got 11 not counting Ramza, and we need 13. We can throw Alma in the mix of this if we want to, but that makes the numbers a bit sketchy for the following part. Likewise, for those dissatisfied with the inclusion of Alicia, Lavian, and Ladd among the 12, we can swap out at least one for Olan Durai, who makes a decent John or Peter to Ramza's Christ.

The idea here is to make a ridiculous comparison to Christ and Arthur, so we need our Judas/Lancelot. We could say Delita, or Gaffgarion (especially because of his presence at the execution grounds, which bear a name suspiciously similar to 'Golgotha'.) or even Argath.

Ramza also shares a number of other parallels with Christ. He faces persecution from the existing government, is of noble birth, is accused of heresy,and is harassed constantly by members of the existing clergy. Oh, and the possibly dying to save Ivalice from the great evils that ran amuck in it.

Ramza is also the only person to have seen The Gods perform miracles via the Zodiac Stones, instead of the unholy monstrosities the Lucavi bent them for.

In any case, Ramza most definitely fulfills the ZBA, if not all the requirements of a Christ-parallel. He had his 12 followers, gathered the Zodiac Stones, and defeated the demon, saving Ivalice. For a Christ-like set-up, he has his 12, as well as other followers. One is a traitor, one is trusted, and he dies for his people's salvation.

Valmafra becomes Orran's wife/lover and the mother to his child(ren).
There wouldn't really be a reason for Valmafra to show up with Orran at Ramza and Alma's 'funeral' with Orran unless the two were somehow involved, since she had only met Ramza once and the two never really knew each other. Obviously, Orran had to have had at least one son, or...no Arazlam.

Ordallia is in just as deep shit during the game's plot
Hence why they aren't invading.

The game's plot is the result of several separate tabletop gaming campaigns featuring a Killer GM and the plot going Off the Rails.

 * The Chapter One campaign, "Cadets of Ivalice", where Ramza's player was Leeroy Jenkins and overall played everything like it was a buddy road movie, Delita's player was trying to roleplay a deep, serious, complicated character, and Algus' player was a total newbie who was just trying to learn the system. As the plot developed, Ramza and Delita grew to disagree about every facet of the game, and Algus, tired of being stuck in the middle, quits after the Sand Rat Cellar battle. The DM continues using Algus as a NPC, exaggerating Algus' previous character to the point of turning him into a Jerkass. The campaign ends with Fort Zeakden, except Rocks Fall, Everyone Dies.
 * Ramza's and Delita's players have a falling out for some time, but since they're friends in "real life" things eventually work out. Delita's player offers to GM a game set in the Yvalice setting, allowing Ramza's player to reuse his character (handwaving how he survived) and bringing on new folks. Except Ramza realizes that Delita is not as over the previous campaign as he thought, since Delita also comes back as a plot-important NPC. While Ramza plays along better this time, having learned his lesson, the new players are not impressed with Delita-as-DM and pulls the plot so off the rails that Delita gets annoyed and throws a freaking demon at the (at this point rather low-level) party. Rocks Fall, Everyone Dies again.
 * Some time later, Ramza takes a turn as a DM running a high-to-epic level party, handing off his character sheet to his girlfriend. Battle one of his campaign? A rematch against Queklain, of course. He also runs a B-campaign starring the Shrine Knights, but since they're all evil-aligned characters the ones who aren't killed by the A-campaign stab each other in the back. Eventually the players left in the B-campaign (including a certain Munchkin who was playing a Badass Grandpa) decide to join in the A-campaign. At this point the party hits epic level, so Ramza ditches the political intrigue portion of the plot and just has everyone go demon-slaying, since they were clearly having more fun doing that than anything else.

Dycedarg is gay.
His friendship with Duke Larg isn't necessarily evidence of this, but when you consider that neither is married despite both being extremely high-ranking lords...