yeah agreed. so far in post timeskip zoro didn't face off against anyone who can make him go all out (excluding fujitora since they just clashed then teamed up against birdcage)
i think King will be the Daz Bones 2.0 of post timeskip, the opponent who Zoro will almost lose to but still win in the end.
Kaido on the other hand will be for the Supernova Trio (Luffy, Law, Kidd) to deal with, and maybe Zoro joins them after he's done with King in final blow as a group effort finishing attack, just to satisfy the fans who want Zoro to be like Ryuma cutting an eastern dragon. it has been made clear that "in a 1v1 always bet on kaido" so it's gonna be all vs one here
but man who am i kidding... it'll probably just end up like this