I think it would be the other way round. McCall was top notch sparring for the star. Fury is not all that, but if he were fighting McCall he would be name used to sell the fight.
JUst thinking here. But would McCall have lost any fights if they were fights to the finish, as they used to be? Probably the Lewis fight (I dont think his "tactics" as he called it, would have worked) but other than this fight, it is hard to imagine anyone knocking him out in a finish fight.