End of the day, I take a 'prime' Shaq over any other center, of any era. He couldn't be stopped. Kareem wouldn't be able to, and I'm not sure even Wilt/Russ could either.
Doesn't mean Shaq had the greatest career, but his peak was better than anyone else's.
Overall career success, I'd go Kareem, Russell, Shaq, Olajawon, Duncan, Chamberlain. I'm not including KG, he was a PF (and the best ever at that).
I just can't get past your rankings, there.
In his peak - which lasted far longer - Wilt was far more of the "he couldn't be stopped" dominating offensive force than Shaq ever was. As Roy points out, a season where you average 50.4 points and 25.7 rebounds is just absurd.
Even from ages 29-36 in the early 70s NBA with a ton of great big-men like Kareem, Cowens, Unseld, Bellamy, Nate Thurmond, Bob Lanier & others, Wilt led the league in rebounding per game in 7 of his last 8 seasons!!!! The one season he _didn't_ lead in that was because he was injured and only played in 12 games. Though, he still averaged, 27.3 ppg & 18.4 rebounds per game at age 33 in those 12 games! He went on to average 20 & 18 the next full season.
Wilt was also a great passer, averaging 4.4 assists per game for his career, which doesn't really do justice. He averaged 8.6 assists per game in '68, which I think is the highest per-game average for a season by a PF or C, ever.
It makes no sense to me that he should be ranked behind Hakeem, Shaq, Duncan or even Kareem.
Wilt was 7-1 and 270-280 lbs. "He couldn't be stopped."
Except by Russell.
I grew up watching the last few years of Wilt & Russell and got to see all those other guys play through their whole careers. Russell and Wilt were, imho, two of the 3 or 4 greatest basketball players to play, ever, at any position. And, imho, easily the #1 & #2 big men.
And that isn't just about 'how weak' their era was. These two guys were world-class athletes by any measure. Russell was a world-class high jumper and middle-distance runner. Same with Wilt, though he also was a stud in the field events (throwing).