Tellah's HP sits about midway between Porom's and Rosa's geometrically - the Zot HP average undersells him because it includes all the bulkiest characters in the game at once. He's 66% of Rosa's HP, which puts him at 61% overall; I'll use that. Still assuming FF4 uses linear+20 for speed since nobody has ever in 20 years being able to explain to me how it actually works, which puts Tellah at around 80% there. Damage is a bit past OHKO to average.
Tellah (FF4) vs Lucius (FE7): Tellah just avoids being doubled to me, I think. Reflect then 2HKO.
Tellah (FF4) vs Ragnar McRyan (DQ4): Faster, 2HKOs? Yeah I don't respect the status much either but I have no idea where this OHKO hype is coming from, even taking the Zot HP average literally; Ragnar is below average for goodness' sake.
Tellah (FF4) vs Tim Rhymeless (WA2): Presumably.
Tellah (FF4) vs Laguna Loire (FF8): lol
Tellah (FF4) vs Emma Hetfield (ACF): lol
Tellah (FF4) vs Rude (FF7)
Tellah (FF4) vs Yam Koo (S1)
Tellah (FF4) vs Arietta (TotA)
Tellah (FF4) vs Boco (FFT)
Tellah (FF4) vs Pikachu (Gen 3)
Tellah (FF4) vs Zoah (CC)
Most of these honestly aren't close. Tellah's... not a Light as far as I'm concerned.
SS is 82% speed, 12HKO damage (Fragile improves it for two attacks, not really worth it considering the MP cost), can heal 27 times, 97/154 for durability.
Sacred Slayer (XF) vs Lucius (FE7): SS is in that same speed range as Tellah, so again should avoid a double to me. Lucius 4HKOs with some light crit, that's... probably enough with counters since SS needs to land like 7 attacks.
Sacred Slayer (XF) vs Ragnar McRyan (DQ4): Sleep weapon miight do it eventually? I dunno, DQ sleep used by slow people is really bad, good chance it does nothing at all, he only has a 10% chance to make SS lose a turn and if SS just healed, that's not good enough anyway (at that point it's 5%). But... damn he has a lot of time to make this work. Yeah, sure.
Sacred Slayer (XF) vs Tim Rhymeless (WA2): Tim builds FP and becomes pretty fearsome.
Sacred Slayer (XF) vs Laguna Loire (FF8): We be seeing limits here.
Sacred Slayer (XF) vs Emma Hetfield (ACF): Emma's pretty scary if you don't put her away fast. Guess what SS never does ever.
Sacred Slayer (XF) vs Rude (FF7): This is really "how much do you respect Rude's speed", FF7 enemy speed is a headache and all. He 2HKOs here so if he doubleturns he wins, but if he never does... blah, SS probably still runs out of MP healing all the damn time. You could take Rude's damage lower, but I really doubt I see PCHP as over 4700 by Rude's final form.
Sacred Slayer (XF) vs Yam Koo (S1): Yep.
Sacred Slayer (XF) vs Arietta (TotA): Oh finally, a mage. Arietta never has better than a 3HKO, and is squishy enough that SS's resources hold up.
Sacred Slayer (XF) vs Boco (FFT): Gross. But the infinite resources prevail.
Sacred Slayer (XF) vs Pikachu (Gen 3): Like Emma, Pikachu must be killed quickly or he will fuck you up.
Sacred Slayer (XF) vs Zoah (CC): Zoah's huge Str gives him really easy heal-locks.
Sacred Slayer seems kinda terrible. With that damage she almost needs to fight mages to not run out of MP.
Locke has about 26% damage but rises to just over double as his HP drops to 1, 68/80 durability, 116% speed. 128% if he goes for his turn 5 instant death weapon.
Locke Cole (FF6) vs Lucius (FE7): Lucius 2HKOs with Divine. Even if Locke doubles weighed-down Lucius, it doesn't matter since ITD is not what you want to be against him as a fighter.
Locke Cole (FF6) vs Ragnar McRyan (DQ4): 2HKOs and has the bulk to withstand Valiant Knife hits in the meantime, even if he takes two boosted ones.
Locke Cole (FF6) vs Tim Rhymeless (WA2): Wing Edge doesn't quite win an instant death race, Valiant Knife does allow for a heal-lock due to a 3-2 + low 3HKO though. That's gotta outrace First Aid.
Locke Cole (FF6) vs Laguna Loire (FF8): Weirdly similar limit fighters in some ways. Going with Locke due to speed.
Locke Cole (FF6) vs Emma Hetfield (ACF): Arc-en-ciel.
Locke Cole (FF6) vs Rude (FF7): Rude has a high 2HKO here, and I doubt Locke has a 3-2.
Locke Cole (FF6) vs Yam Koo (S1): Faster so should win the slugfest.
Locke Cole (FF6) vs Arietta (TotA): Arietta is bad.
Locke Cole (FF6) vs Boco (FFT): Pretty sure Locke goes Wing Edge here to avoid counters. He still probably 4HKOS anyway? Boco stalling for Choco Cure doesn't help since instant death. Boco probably 4HKOs back, but slower obviously.
Locke Cole (FF6) vs Pikachu (Gen 3): Think so.
Locke Cole (FF6) vs Zoah (CC): Zoah's definitely M/L borderline and tends to win these sorts of slugfests with little difficulty. Actually it's possible he even one-rounds? Doesn't have to.
Lucca's got a borderline 2HKO, 87% speed, 68/127 durability (but can get crazy mdur if she needs).
Lucca Ashtear (CT) vs Lucius (FE7): Taban Helm setup means Lucius needs way, way too much time, while Lucca still 4HKOs.
Lucca Ashtear (CT) vs Ragnar McRyan (DQ4): Lucca's best bet is sleep/protect so that she's only 3HKOed, then kill with 4 Flares. Wait, fire res, 5. That's probably too much, Lucca needs too many dicerolls with sleep to go her way.
Lucca Ashtear (CT) vs Tim Rhymeless (WA2): Sleep is devastating to slow opponents like Tim.
Lucca Ashtear (CT) vs Laguna Loire (FF8): Sleep -> Protect -> 2HKO.
Lucca Ashtear (CT) vs Emma Hetfield (ACF): Vigil Hat plus being generally better.
Lucca Ashtear (CT) vs Rude (FF7): I mean Rude probably didn't need fire absorbing here but yeaaaah.
Lucca Ashtear (CT) vs Yam Koo (S1): Kneejerk Yam Koo but... he may just miss all the thresholds he needs? Just misses a 3HKO, just misses a 3-2, just gets 2HKOed. Okay never mind.
Lucca Ashtear (CT) vs Arietta (TotA): Lucca vs pure mage.
Lucca Ashtear (CT) vs Boco (FFT): I really doubt 48 faith is enough here, Lucca still powers past Choco Cure pretty easily and Boco's HP is wretched. They're also almost identical in speed unless you compare Boco to PCs with no equipment.
Lucca Ashtear (CT) vs Pikachu (Gen 3): Gen 3 Pikachu pretty reliant on magic to get things done, and Lucca immunes paralysis.
Lucca Ashtear (CT) vs Zoah (CC): Pretty sure Zoah is faster, which settles any argument.
Rico is 74% speed, average damage, 178/95 durability (huh, better than I'd have guessed), has some trashy buffs.
Rico Banderas (XG) vs Lucius (FE7): Okay finally someone Lucius doubles. Get wrecked.
Rico Banderas (XG) vs Ragnar McRyan (DQ4): Both like 5HKO each other? Rico is faster? Again Sword of Lethargy is turn 10 to actually deprive a turn from someone, let's not hype that against non-healers please. Only thing that might tilt this for me is Swordedge Armour or whatever it's called... might well by Ragnar a 4HKO. Sure.
Rico Banderas (XG) vs Tim Rhymeless (WA2): Tim is marginally faster and Arcana 13 probably lands in two tries against Rico MDef.
Rico Banderas (XG) vs Laguna Loire (FF8): I guess he can backload damage some at worst.
Rico Banderas (XG) vs Emma Hetfield (ACF): Speed is almost tied, but even if Rico goes first he can't OHKO and even if his blockers are good enough, Great Booster + heal + either magic damage or try to sneak some status through.
Rico Banderas (XG) vs Rude (FF7): Probably. Rico likely 3HKOs to me while Rude needs at least 4. 4-3 is possible I guess, but since Rude also needs a damage call here, I'll go with Rico.
Rico Banderas (XG) vs Yam Koo (S1): Yam Koo has a 6HKO but he has a 6-4, so he just needs to dodge Rico once. Do I respect Rico's accuracy? Hahaha good one guys.
Rico Banderas (XG) vs Arietta (TotA): Arietta is certainly faster and hits Rico's bad mdur but... yeah he still 2HKOs her and the full-HP shot just doesn't hurt.
Rico Banderas (XG) vs Boco (FFT): Overpowers Choco Cure at base, Boco does get counters and so forth but Rico pdur too strong.
Rico Banderas (XG) vs Pikachu (Gen 3): Earth elemental? Yeah sure.
Rico Banderas (XG) vs Zoah (CC): Rico is probably bulkier, but Zoah has both speed and damage.
Tellah 11-0
Lucca 8-3
Rico 6-5
Locke 5-6
Sacred Slayer 1-10
Rico's pdur made him a bit better than I expected, but still Light. Otherwise Tellah/Lucca M (Lucca lower), Locke L, Sacred Slayer low-L sounds right.