I think what separates or differentiates Bill Russell from many of these other names mentioned is the level of racial bias that he was subjected to, particularly at the beginning of his NBA career. Things changed a lot between 1957 (the start of his NBA career) and 1969 when he retired but I think due to his timing and some of the places that the NBA took him to, he was really subjected to a lot of racial bias that at least the more contemporary athletes were not. Kareem for example entered the league in 1969. I am sure that he faced his share even at that time but nothing compared to the state of things when Bill Russell was playing.
If this question is just about on court performance, there are certainly athletes from basketball and other sports that are in Bill Russell's class. You could probably come up with 5-10 just in basketball. It gets harder if you are trying to compare Bobby Orr or a tennis player or whatever. But to me, if you only look at the basketball aspect, you are missing the key thing that really separated Bill Russell from most others.