Some guys are quicker in different ways....You mentioned Jones...Roy held his left low a lot...This helps the speed of a punch for some reason you punch faster going up...Same as Whitiker, Ali in a way when moving held his hands low to punch...But you also have to be overall fast or you get caught. Guys like Tyso build momentum when punching in combos so once the body gets going....I agree on Mosley....Shane had some fast combos. still does but when he was younger....