Not many, imo. RJJ sucks. Pac and Floyd would be horrible as well despite their skills. I think Ward and especially Marquez would be great trainers.
Floyd's ego is his main downfall, it's all about him Manny is a freak athlete, he wouldn't be working with anyone the same as him, similar to RJJ I agree with Ward and 100% marquez who has top level I.Q Hopkins?? The guy is crafty as an old fox I think Lennox Lewis could be another It's difficult to say Elite athletes rarely make top coaches, evidenced in football/soccer
Hmmm we would never really know tbh. Hopkins seems an obvious choice but I could see him not getting on with a lot of modern fighters in all honesty. I may be wrong. Similar to Paulie Malignaggi, knows the game inside out but how would he get on at coaching individuals. Who knows
Alexander Povetkin. Very, very kind/modest guy, and extremely technically skilled fighter. He could teach a lot to a decent boxer.
Concur on Ward! If you want to learn how to head-butt, hit below the belt and after the bell then Ward is your guy!