Re: Which influences the choice of a fighter’s style more?
All of it and more.
A boxer's inspiration may be different from his or her stylistic influences. WBC Women's Super Bantamweight champ Alejandra Marina Oliveras says her inspiration and influence is Mike Tyson, and she fights like it. Her nickname is Locomotora and it suits her.
As an amateur, my inspiration was Muhammad Ali, but his style was totally unsuited to my physical abilities. Sure, I was tall and rangy for a lightweight (5'11"), but I wasn't quick, fluid or gifted with defensive brilliance. My stylistic influences were more like Danny "Little Red" Lopez and Roberto Duran. Duran made me appreciate that a shorter guy could indeed use a jab just as effectively as a taller guy.
Training is critical, and not always necessarily in a positive way. Personally, I don't believe that Floyd Mayweather Sr. has been a good influence on Oscar DLH. Oscar was at his best when he used what George Foreman called "crow hopping" foot movement. DLH really did have a predatory look about him when he used that style to move in and out, picking opponents apart. The less mobile, shoulder rolling semi-copy of PBF doesn't suit Oscar.
Experience and adaptability are major factors. George Foreman demonstrated that during his comeback. Some boxers, like Shane Mosley, Muhammad Ali and Sugar Ray Robinson, demonstrated the ability to adapt mid-fight.
Natural athletic ability is the least important of these factors. Rocky Marciano proved that. Has any successful champ done more with less?