I think Cotto has more of a chance than Mayweather. I actually think Cotto is going to win. Mayweather would get knocked out. He's scared of a fight. Pacquiao would maul him and knock him out early i think.
He's beatable. All he needs to do is to mess around with his training and conditioning, and not follow the team's gameplan, and he'll be vulnerable as hell. It's a testament to his work ethic and desire to succeed that he has only been defeated a couple of times since he jumped from 112, skipping 115 and 118, to stay put at 122, and with every succeeding weight class jump after that.