how would anyone know he cant beat kuma he's a robot completely now.
Because Kuma would just absorb the blows on his pads, sends Zoro flying, any other tricks he has up his sleeve.
Come on man don't underestimate Kuma, he obviously didn't become any weaker since he became a robot.
Ontopic: I think that Moria is the weakest, but it still won't be an easy fight with zombies, brick bat and his doppleganger but I think Zoro can beat him.
As for the rest I at least hope so that Zoro isn't able in beating them yet.