@jrm: Cain might be the greatest HW ever, so I'm not going to hold that against Brock to much. At the very least Brock was a top 10 HW. Punk wouldn't even be a top 10 MW in Bellator.
Joe Rogan could beat him in a fight right now. I wish I was kidding. Punk is only a white belt in BJJ, he says he studied Kempo when he was a growing up. Kempo is a joke in MMA.