Chef Hat vs Bandana- Serge should OHKO Quina before they move and that puts a real damper on anything else the Chefs could do.
Chef Hat vs Baseball Cap- Ness equips for sleep blocking and proceeds to hand them the entire asses on a platter. Junpei is helping.
Chef Hat vs Sombrero Orcha isn't quite one-rounded by the weakness-boosted Hydropump plus Ricardo's move, but he can only heal once. Meanwhile it would take two rounds of concentrated attacks to take out Quina, so three with the heal. What's Quina got with three turns? Wellllll... if you spot them an insomniac, and I suppose I do, that. Thanks Shadow Hearts for being the only RPG with good status blockers but no sleep status! Put everyone else to sleep and slowly 1v1 Ludicolo to death (basically white wind to outpace Hydropump's damage until those run out of PP), after which Ricardo... he could maybe beat Quina solo but not with them having added damage from an ally.
Bandana vs Baseball Cap- Locke and Serge can't tag team Ness to kill him before his first turn, meaning that Serge's actual weaknesses as a fighter (like the fact he gives up his entire second turn to go ham on someone) actually matter. Ness' move here is probably to drop a Flash Omega, which almost certainly takes Serge out of the fight entirely and lands sometehing on Locke that lets Junpei win a one on one.
Bandana vs Sombrero- Hey, Ricardo has an ally to buff! Unfortunately Ludicolo is damn near only grass type in the entire franchise to not get a sleep or paralysis move, so Serge OHKOs them after they get off one Hydropump and that's that.
Baseball Cap vs Sombrero- Pokemon having no status blockers whatsoever, meaning Flash Omega does grisly nastiness no matter the RNG, inclines me to stop the analysis there because Ricardo sure ain't soloing Ness.
<Ness> Let Me Solo Them