FF8 characters definitely limit at ~33%, no need for dead allies or status or anything like that.
The interp question is whether the character limits in time if they are chipped to 31% health or the like, since you have to hammer the menu button longer at higher HP, so there is a bit of a lag before the limit actually comes up. Assuming the player is even half-decent at hitting a button quickly and then stopping when a distinctive tone sounds, though, an FF8 character shouldn't get lapped while waiting for the limit to come up unless they're facing WA4 boss-level speed. Admittedly, if it's relevant for anyone, it's relevant for Selphie since she then has to spend MORE time looking for a Full Cure... but against Ard level speed, that's not really an issue.
Fei Fong Wong (XG) vs Celia (FFT) - This really is a tie, but inclined to tiebreak against Fei because Maria in the land-averages making everyone else look awesome is slightly shaky. She's blatantly meant to be a mech-only character even if they do force you to use her for one dungeon. If she's counted even slightly less in the averages, the average speed goes up a bit and Fei loses the tiebreak.
Richard (S5) vs Nephenee (FE9) - Oooh good match. Inclined to think that Nephenee doesn't quite make the 2HKO, though.
Jean (Lunar:EBC) vs Yulie Ahtreide (WA4) - Lack of respect for Yulie's ability to pressure means that even if it takes some time for Jean to status Yulie, she has it.
Baal (G1) vs Kain Highwind (FF4) - .. man, the stat topic claims that Kain's damage is worse than I remembered. Because if his jump could even do a mere ~50% PCHP or so, I'd be inclined to let him win.
Ard (WA2) vs Selphie Tilmitt (FF8) - See above.