We don't really know how good Bruce was as a martial artist as he never competed in open tournaments.
It does amuse though when people say that Bruce could have beaten any martial artist past and present. That would never have happened!
Bruce, I'm sure, would have been a real handful at his weight. Which was probably not more than 140pds.
But, up against a much bigger martial artist, he would have been flattened very quickly.
That's why they have weight divisions in boxing, judo, wrestling, mixed martial arts etc.