Had Redgrave been black and from Harlem and he’d changed his religion to Jedi halfway through his career, would it of made his achievements any greater?
Well, yes, possibly, if the doing of those things greatly endangered his ability to achieve those achievements. It’s easy from 40 years later to forget how potent the forces of segregation and racism were – there were many people who attempted to end Ali’s career for his political and religous beliefs.
The difference is between being quite good at games and being a great person – Ali was a good sportsman, but also entertaining and engaging, and a man of principle, and who was a participant in pivotal and zeitgeisty events. Redgrave is just some guy that won ribbons for moving the boats fastest. Ali was a lightning rod for the conflicts emerging out of the civil rights struggle. Redgrave is a tedious man in a boring sport.
The question is fatuous.