well....
put brock lesnar against rashad evans and brock would murder him...
rashad said himself that he takes shane carwin to spar with him because there's no way in hell to get better resistance in his fight training, that if he's able to sparr with him then there should be no problem taking out an opponent 60lbs lighter.
big/skilled fighter against small/skilled fighter = big/skilled fighter wins
big/no skills dude against small/skilled fighter = small/skilled fighter wins