this question was knocked around before, when someone called squadfather on his claim regarding cotto (saying that he'd kick cotto's ass).
somebody in that thread put it out in black and white: would, say, michael carbajal in his prime - carbajal being one of the best boxers ever, but extremely tiny - beat a 300lbs (with abs) bodybuilder, big as a house but thick as a brick mentally with no fighting skills?
in other words, everything in life is a question of balance...even something as lowly as a street fight.