Knights (FF1 Knight, FF5 Knight, Squall, Steiner) vs. Archers (FF3 Ranger, FF5 Ranger, FFT Archer [male], FFX-2 Gunner Paine)
Archer damage is good but spread out and hitting a bunch of extreme physical tanks and risks turning on Squall's limit. The Knights kill whoever they like meanwhile.
Thieves (Locke, FFT Thief [female], Zidane, Rikku*) vs. Engineers (FF4 Cid, Edgar, Mustadio, Worker 8)
Rikku status out Edgar somehow then dismantles the only robot in the tourney later. She practically solos. (Alternatively she lets FFT Thief seduce Edgar?!)
Dancers (FF5 Dancer, Mog, FFT Dancer, FFTA2 Penelo) vs. Ninjas (FF1 Ninja, Edge, Shadow, Yuffie)
Yuffie & Shadow must kill Penelo ASAP, but that's doable. FF5 Dancer is a threat but kind of random, the rest of the team gets going too slowly. Good luck off Nameless Dance might turn this but it'd have to be REALLY good luck.
Blue Mages (FF5 Blue Mage, Strago, Quistis, Quina) vs. Dark Knights (FF3 Dark Knight, DK Cecil, PC Gafgarion, PC Seifer)
Sure, I'll buy the blitz strategy. I forgot that Quina was so freaking slow.
Black Mages (Palom, FF5 Black Mage, Vivi, Lulu) vs. Squires (Gogo**, Cloud, Ramza, Kimahri)
Uhhhhhhh. Comes down to a speedbreak between Vivi & Gogo I think. Lulu basically solos the non-Gogo Squires effortlessly (lulz Ultima), so the BMs just need to kill Gogo... which is unusually difficult. Palom needs to die, so Cloud OHKOs him with the Ultima Weapon, but Ramza & Kimahri can't combine to kill anyone else, fail. FF5BM + Vivi damage should kill Gogo... barely... or they could do some kind of status blitz, alternatively, although MBlock can randomly screw up either strategy. Problem is that Vivi & Gogo are practically tied in speed. If Gogo wins the speed-off, he Sour Mouths Lulu (Noiseblaster not a good idea, lots of this team including Lulu can resist Confuse), although even that might miss. If it does hit, though, then the rest of the Squires can easily clean up the remaining living 2 Black Mages. Coinflippy, but leaning Black Mages, which is kinda pathetic this is that close. Get some speed, guys.
FWIW, Sneak Ring-less Gogo is 30 Spd to an average that's either 33 or 36, and might have some vague way to tweak upward. Vivi is 21 to a 25 speed average.
EDIT: Sure I'll buy super's hype about Gogo outracing Vivi & his status being better than FF5BM's.
Bards (FF3 Bard, Edward, FF5 Bard, FFX-2 Songstress Yuna) vs. Dragoons (FF3 Dragoon, Kain, FF7 Cid, Freya)
Yuna is totally a Dancer but dang if the class title doesn't indicate she's a bard. Anyway FF3 Dragoon is the only one fast enough to smash Songstress, which is not that hard, but he barely misses the OHKO, then the entire Dragoon team eats Stop.
Time Mages (FF5 Time Mage***, FFT Time Mage [female], Tidus) vs. Red Mages (FF1 Red Wizard, Tellah, FF5 Red Mage, Vanille)
We all know how insane Tidus is from the old Dungeon days. Sonic Steel -> Hastega -> Slowga -> Quick/Quartr/Quartr, then Time Mage clubs red wizards on their head to finish 'em off and doesn't even bother with Short Charged Meteors. RWs might get 1 turn, but anything defensive like X-Magic Life is a waste, they need to do something significant and fight-turning like smash Time Mage or Tidus, and it isn't happening.
Summoners (Rydia, FF5 Summoner, FFT Summoner [female], Garnet) vs. Paladins (Cecil, Agrias, Meliadoul, PC Beatrix)
Garnet nulls Holy... so Beatrix has to nuke someone else, but Garnet can either revive them or throw down MT 50% ID to try and get Cecil or Beatrix. Agrias & Meliadoul kill Garnet, but then the Paldins probably just get nuked by 3x incoming MT damage. I think.
Samurai (FF5 Samurai, Cyan, FFT Samurai [male], Auron) vs. White Mages (FF3 Devout, Rosa, FF5 White Mage, Eiko)
FF5 Samurai has a great start with GP Rain, and Auron can throw down Zombie break on someone, but I think the White Mages just heal it all off then status FF5 Samurai? This actually seems closeish, the Sams might yet have a long-game if Auron can spread the Zombie love around enough to get past the pile of healing & revival. Flip side they might murder their own comrade with the MT healing if they're not careful. Eiko resolving 2 Madeens ever is trouble, so suspect she's target #1 for the Samurai. Any thoughts?
EDIT: See below, FF5 Samurai doesn't get a 2nd turn, that is bad news.
Monks (Grand Master, Sabin, Zell, Amarant) vs. Monsters (Gau, Cait Sith, Vincent, Red XIII)
The Monks UTTERLY FAIL at chipping around Cait Sith's healing limit short of really good luck on Bum Rush targeting, which is 1/4 a chance. Yeah no, if they wait too long they're all frogs.