Overeem isn't even close to the best striker to ever step into the hw class, can the guy throw fists yes without a doubt he can. But he its definitely past his prime in my opinion 14 years fighting with 8 years at the top level the guy just isn't what he use to be. can he best brock, yes standing up sure anything is possible.but after brock takes him to the ground its going to be over. I just don't think overeem is going to be able to hang with brock on the ground. I see brock taking this by ground and pound in the second round when he takes him down and beats his old face through the back of his head.
Brock is a young fighter and does make a lot of young fighter mistakes, so out is possible, but unlikely