While Brock's wrestling is top notch I just haven't seen him incorporate it very well into MMA. His wins have come largely from overwhelming people with his physicality (Couture, Herring, Mir 2). He did have some good takedowns the first time with Mir but for having the wrestling pedigree he has he has not used it like say Sonnen. Lastly between Carwin and Cain the guy is very hittable. With his lack of true mixed martial arts and standup defense I just don't see him being able to beat a solid veteran like Overeem. If he can get the fight down he can dish out some serious punishment so he has a shot. Maybe Overeem will gas like Carwin