Haven't bothered to morurun Rick yet, but that's a really good idea. Shoulda thought of it myself, tbh.
Not sure if you know, but Train Slashes are still subject to your character's accuracy; meaning they can miss just like any other attack (only meaningful difference seems to be the lack of the accuracy penalty you'd get with Melee attack 3 onwards). Also, like I said, my Bear has 192 accuracy and still can't hit Kaito reliably in world 3. Safe to say I have no high hopes that a fully morurun'd Rick will do any better.
As far as Rocky goes, yea, he's got his Tolerances max'd out, 82 Evasion and is generally just focussed on tanking without getting stunned too easily. In other words, all of his skill points are spent on survivability, with nothing left to give him more "Ally Guard" moves, so for now he's stuck with 3 in those, and 3 in Defensive Stance, which also buffs his defenses. He's no MVP but he does his job as is well enough, as in keeping everyone else alive to deal damage. I'd bet with his occasional deflections, he'd likely survive the whole fight if I don't run out of heals.