Swordskillers vs. Dragons
Agrias, Meliadoul, Beowulf (FFT) vs. Zog (BoF1), Sara (BoF1) and Ryu (BoF1): I actually don't see any way for Team Swordskillers to kill Ryu on turn 1 at all, unless you let a Beowulf status get him through dragon immunity. Even with his armour destroyed, Ryu is extremely tanky due to his ridiculous shield + dragon def boost, I can't see any way for this team to 3HKO him with physicals (hell, they have trouble doing it to average). So he's getting an attack off, and has a MT 2HKO, and Char/Gale even halved by White Robe is going to add up to some serious wreckage. (Alternatively, Sara just uses her ITE physical to finish off the biggest threat, probably Beowulf). Even if Agrias/Meliadoul down Ryu on turn 2, they haven't healed yet and will likely be finished off.
Speedrun vs Ladies Men
Jeremy (WA4), Tidus (FFX), Jet (WA3) vs. Edgar (FF6), Zelos (ToS), Ronfar (Lunar 2): Yeah Edgar can survive a Jeremy turn, too bad so sad that Jeremy gets three before he gets one (and possibly Zelos too, but 2 at worst, I'm not touching that ARPG speed interp).
Clones vs Valentines
Chaz (PS4), Claude (SO2), Cress (ToP) vs. Keith Valentine (SH1), Joachim Valentine (SH2), Hilda Valentine (SH3): The clones are all faster, Chaz has a MT 2HKO and the others have ST 2HKOs. So only one Valentine gets a turn.
Boss Rush vs Ragnarok
Lassic (PSes), Marcello (DQ8), Jenova (FF7) vs Hrist (VP2), Ull (VP2), Surt (VP1): Lashiec's AnotherGate is by far the most impressive MT offence in this fight... Marcello might well be second. Hrist/Ull/Surt are too ST focused here, for all that they do have the right elements for taking down Lashiec.