Assuming it goes
Kizaru -> Shiryu -> Mihawk
I don't think it would be that bad
2v1's Kizaru -> Shiryu randomly does something that hypes him up to Beckman's level or above -> Zoro beats him and gets a power up/masters ACoC during the fight -> Fights Mihawk and wins
Or something
I honestly don't see how Zoro beating Kizaru solo here makes sense BUT I can see where you're coming from
Yeah Shiryu losing to Zoro
after Kizaru makes no sense, at least with the way that Shiryu has been presented so far.
I mean, if Shiryu is as strong as some people say he is, he shouldn't even need to get involved in the fight the way that he did. If it wasn't clear before, it's definitely obvious now that the whole reason Shiryu is dangerous is because he's unpredictable, sneaky, and underhanded. Not necessarily because he's the best fighter around.
So with that being said, I don't necessarily expect Zoro to solo Kizaru this arc. In fact, I fully expect that it'll be a team/group endeavor unless Luffy fights him. Actually I'd even go so far as to say that Oda would likely let an external ally defeat Kizaru before he'd let Zoro do it. But that doesn't mean I'm happy about it lol