You definitely have a point about the groupings. The antagonistic trio are there together, while these other 4 are here. That being said...i will always think Mihawk is an exception. He's just not Luffy's antagonist or milestone.
I do think Kuma still has a shot, yes. Hancock is....difficult by virtue of her not being around. Kuma has a DF that is allowing him to be relevant here and now.