Don't get me wrong, I know it would it would be an awful idea to actually cast wrestlers and combat sport guys in films as primarchs, it's just that they more easily come to mind for me when I'm reading HH books and need faces for the characters. Probably because they're (usually) big and (usually) look tough already. It's not too much of a stretch for me to picture Mike Tyson as Angron
Actually my first post in this thread should have been Dolph Lundgren as Rogal Dorn. A genuine actor and hardman.