Godlike
Haken Browning, Kaguya Nanbu, KOS-MOS, Xiaomu (SRWOG:Endless Frontier) vs. Asellus, WhiteRose, Mesarthim, Meilin, Riki (Saga Frontier) - Mesarthim goes first, StasisRunes Haken and the battle goes downhill fast. Asellus+White Rose 100% MT ID comboing goes before everybody left in this party and the end, unless you can argue me Haken somehow outlasts through Snipe spam a full SaGa party with this much revival and cheese (answer: you can't). Hilariously, if I actually decided for Suzuka in this, the fight might've gone differently with ENCHAIN HYPE. So strange. -Regardless-, there are multiple ways the SaGa entourage can win this fight (many of them including Riki's rings: just the status immunity ring utterly mangles the Snipe => Glare strategy the EF party needs to win), but this one is elegantly foolproof. EDIT: Ahahaha, rings are initiative, the EF party would be screwed regardless forever.
Belial (Wild Arms 4) vs. Chris, Geddoe, Hugo, Sasarai, Luc, Emily (Suikoden 3) - Belial's 2.88x PC HP unscaled, her shield is 1.53x PC HP (!!!) unscaled -before- the damage halving - i.e. it takes hits better than Belial herself when not facing MT. Meanwhile, only Sasarai, Luc and Geddoe can break through it via MT. -However, she needs to open with Distortion to avoid Emily 3HKOing her ass. So, Distortion, Emily rams into Distortion, 4D Pocket Geddoe, Hugo and Chris ram into Distortion. At this point, the shield took about 2x PC HP worth of damage and can still take 1x PC HP more and nobody damaged Beli yet. If Sasarai Earthquakes instead of LoE, he gets to deal some damage to both shield and Belial, but this is barely enough to take the shield out and she's about to get another turn, with which she can 4D Luc... actually, I'm not sure, she's liable to be overwhelmed anyway because there are -three- PCs with nasty MT and any turn she spends unshielded means she gets brutally bumrushed. If 4D Pocket didn't run out, maybe I'd see her winning. Eh.
Jenna Angel (Digital Devil Saga) vs. Razeluxe Meitzen, Etward Dysler, Lilianne Valendorf, Puniyo, Yun (Mana Khemia 2) - I dunno. Every trick Jenna can pull feels like it gets answered by "I'm Puniyo and I MT heal+revive+statusheal on command" swap-in-out cheese. Past that, the team has enough elemental variety to mostly deal with Jenna's orbs and can cheese all her other options while having tons of offense. EDIT: Oh dear, Glaceration has an argument to break past Jenna's shield immunity too, bypassing the orbs. That's just weird, for all that it turns Lily into a walking kick me sign.
Heavy
White Mage, Summoner, Ninja, Samurai (Final Fantasy 5) vs. Yuri, Kurando, Joachim, and Anastasia (Shadow Hearts 2) - Samurai+Ninja get Yuri killed before he gets a turn and then it's all downhill for the SH team. Without Yuri, they can't even outpace the opening offense dealt by Gil Toss...
Ghaleon (Lunar:SSSC) vs. Myria (Breath of Fire 3) - I want to say that the speed difference at least cancels out the damage edge Ghaleon has... but his durability edge -is- significant. Chaos Shield's still useless, at least, because lololol sanctuary, so Ghal ain't even touching that. But I don't think Myria3 can -quite- handle the roughly 4x extra PC HP Ghaleon likely has here, even though it's close. If she actually managed a 3-1 split, I'd probably vote her way, but don't think she's -quite- that good, low 2HKO isn't what you want against Ghaleon unless you're running off above 2x average speed.
The Dark One (Arc the Lad 2) vs. Kornell 3 + Violetta 1 (Grandia 3) - You more or less don't outslug the Dark One in a fair, straight slugfest in this setting. He probably has multiple times the HP of both these guys combined -before- any damage reduction from defenses comes to play.
Middle
Ness, Paula, Jeff, Poo (Earthbound) vs. Loki (Valkyrie Profile) - Loki instantly OHKOs Paula with unreflectable magic or physicals that are MT - by the way, this easily 2HKOs everybody but Ness. If you see average HP as below 45k in VP, he also OHKOs Jeff, but Jeff is worthless anyway. So, this is basically Ness and Poo vs. MT damage of both flavors they can't entirely wall and the minute Poo dies Ness is eating an Indiscriminate OHKO. Not to mention that, without Paula, they have zilch chance of outslugging Loki ever: assuming a 40k damage average against Loki (and that may sound pretty goddamn high for a lot of people), he has 4x PC HP roughly. If Ness and Poo -both- devote all their PP to offense, they manage... 3.2x PC HP, and their physicals are egregious failure against everything not named Axem Green, let alone Loki. If they can't outslug him even without spending a penny on healing (which is asking for immediate death), I suspect that even allowing shit like rolling meters, they run out of resources before even making any appreciable leeway. The only person who can actually devote offense (and bad offense at that. People, Paula freaking -4HKOs- average with Freeze Omega) against Loki gets overkilled by everything he does and everybody else is utterly tied up. EDIT: PAULA ENDS UP ON THE WRONG SIDE OF AVERAGE SPEED WHAT THE FLYING FUCK. Paula keeps finding new ways to fail harder than Kevin Winnicot in a tutu.
Apocrypha (Radiant Historia) vs. Dorothy, Strawman, Lion and Tin Man (Wizard of Oz) - You know what? If I allow Mirror Skin to block Apocrypha's status spells, Dorothy isn't that far from soloing Apocrypha as is -unscaled-. In doubt, kneejerking against Apocrypha who can cry me a river over being amazingly inflated in the DL setting feels okay enough. Since he can't OHKO Dorothy with anything to me -either-...
Cthulhu, Umi, Dacre, October (Cthulhu Saves The World) vs. Exor (Super Mario RPG) - EDIT: Right, Exor is a lategame SMRPG boss and MT match-winning status looooooooooooool.
Melfice (Grandia 2) vs. Stocke, Aht, Eruca (Radiant Historia) - Holy crap Melfice gets parts and mangles Aht and Eruca so bad.
Light
Zed, Jane, Emma (WA:ACF) vs. Edna (Shadow Hearts 3) - Follow Me+Great Booster = not enough, Zed is the only one dealing damage here. Edna certainly one-rounds Emma and Zed is likely to run out of really safe damage before he can kill Eddie.
Luca Blight (Suikoden 2) vs. Zalera (Final Fantasy Tactics) - EDIT: nvm
Serge, Glenn, Irenes (Chrono Cross) vs. Marcello (Dragon Quest 8) - um no.
Pikachu, Blastoise, Charizard, Venusaur, Snorlax, Lapras (Pokemon) vs. Peppita, Albel, Adray (Star Ocean 3) - EDIT: the outnumbering actually goes the other way. Nevermind, Poké in this setting can't win against teams ever unless they're made of BoF1 scrubs.