How good can cotto be with just a left hand?

Cotto simply has no right hand what so ever and is drastically inferior on that side. All his right hand punches do are try and aid a left hand. This factor versus a south paw can be devastating tactically. He really has a much more limited range of tactics as we saw the repetitive attempts of left hooks. If only he forced himself to train his right hand more, potentially even training southpaw to reinforce its range of motion, coordination, and athleticism. However, that is all speculation. Any other successful fighters besides joe frazier can you think of with just one hand and how it played out for them.(BTW I already saw the video of a fighter getting ko after dislocating his right arm)