Zoro may be an ACoC user a thousand years later, for now he just began generate CoC and Kaidou recognized him as CoC user. doesnt matter since his overall haki is so below Luffy. Now we know WSS is =/= stronger fighter, since Shanks has extreme CoC and no one recognize Mihawk for CoC.
So however strong WSS is, Shanks is not at all weaker as a fighter than that WSS, and really is stronger. You assuming Mihawk has CoC has no basis whatsoever, since thats the only excuse left since the CoC you mocked as fodder control before, apparently is the strongest power now. So embarassing.