THe sooner the fighter starts with a good trainer the better. IF they group with a great trainer it really helps out, and makes them a better fighter. However, the trainer has to understand what strengths the fighter inherently has, and what weaknesses he naturally possesses as well. Its not just about any fighter going with any trainer, because each trainer likes to train a specific type of fighter. Steward like the tall fighters that have a good jab and right cross, Floyd Mayweather SR. likes the speedy slick fighters, Roy Jones Snr like the incredibly fast fighters (Gainer, RJJ, Mundine). Buddy likes washed up or bad fighters. The one coach who I think can really adapt and train a lot of styles is Freddie Roach, and I think it would be a benefit for any fighter to go to him. He doesn't really train guys to change their style, he integrates pieces into the style they already have which takes a lot of knowledge of both different styles, and training techniques on Roach's part.