If he outweighed him by a 100 I'll rock with Tyson. @Steve0x Lee was much more than just an "actor." I'm pretty sure he mastered his own style and had many who wanted him to train them. Also, pretty sure Chuck Norris was his pupil at one point.
Onto Floyd vs Tyson, go back and watch old Tyson training and film. Before his trainer passed, he was an absolute freak. Punching, defense, footwork, EVERYTHING. HE was a strong boxer, but what added was his body control and feet.