The problem with trying to have it both ways: dumbass gag explanations define the series, and yet this is a serious plot where that would obviously just mean lazy writing. S-Hawk has the mind and skills of adult Mihawk with an identical sword, but his own personality despite no will of his own, abilities outside of Mihawk's scope, and no ability to process the relationship with Zoro which would have come about before they were created. For examples. These are things I think Oda would just half ass with explaining since he hasn't bothered yet