That's a mind boggling list. I would have loved to have sat down with a man like that and listened to his anecdotes. Incredible.
It's actually harder to pick the best trainer as opposed to picking the best boxer. I think there are probably a dozen or so that honestly you'd be splitting hairs by picking one over the other. Also, so much of their work, work we don't get to see, is done behind closed doors. I also think that there have been some fine trainers that never got the chance to work with top talent. I think the talent of the fighter has a lot to do with the success of the trainer.
Had I completed my amateur days as highly as I wished I dreamed about trained by Freddie Brown and Ray Arcel. The knowledge and skill these two had from decades working with all manner of fighters is something else. George Benton is another whose skill as a trainer I thought very highly of along with Willy Pep's trainer, Bill Gore.