When Mayweather shoots his springing right hand lead from his high guard position against southpaws ( Judah in particular), he will either land it flush or or misses . But because he is coming in at such force and covers so much distance( he really is leaping in), the southpaw opponent is forced into a half clinch because mayweathers body smothers them right up. He also bends to his left as the right is being thrown with his left hand on his ear. This is so he can slip any cross counter and block any lead hook counter from the southpaw. Because he cant use the jab to the body as effectively against southpaws, this is his punch he uses to disrupt the rhythm of the southpaw. Pac has a rhythm and will hate this punch coming at him all night.
With the way Gayweather fights now, he is susceptible to body punches. His feet is not mobile but his trunk is. His high guard protects the head well, especially since he tends to present his fklank which makes the target smaller but his body is vulnerable. A good body puncher can sneak a punch or two then move out. Repeatedly done, it would eventually crumble.
He does not even fight like that anymore. He seldom throws anything, a little flatfooted, and very very defensive. Would you think he would have stood toe to toe with Mosley if he had the mobility he had like against Coprley?