I suppose if you have to lift rocks for a living excesive muscle mass might come in handy, but I think it's funny that people associate it with fighting ability. Being a croissant-headed mesomorph doesn't mean you have skilz. Look at the most dangerous guys in every division of the UFC and you'll see what I mean.

BTW: I've met and like both, Blades and mreyns, so I'm not taking sides.