The argument I have with the Tyson Fedor comparison is that Tyson fought everyone he could during his reign and he didn't avoid anyone. People argue he avoided Evander but they did wind up fighting. There are MANY fighters Fedor could have fought and didn't... even when he was in Pride he never faced Sergei, Werdum (who later beat him) or Barnett. After that Couture, then many challenges awaited for him in the UFC that he did not face. Then Overeem. So many fighters Fedor avoided facing up to now at his relatively young age of 34.
For one, Tyson never fought Holyfield before his jail sentence he fought Buster Douglas in Toyko instead (and lost) he thought Holyfield later in his career and lost twice.
I'm not knocking Tyson, pre jail he cleaned up the division and unified the title but it just so happened the heavyweight division was weak at the time.
Fedor also pretty much cleaned up the Pride talent pool in similar fashion. Tyson's jail sentence lead to him not fighting Bowe, the biggest name on tyson record (he beat) is Larry Holmes we would old and well past his prime (sort of like Tyson himself was against Williams) after that? Michael Spinks I suppose or Ruddock (tyson never fought Ray Mercer, Oliver McCall)
Tyson could have taken tougher challenges than he did before Holyfield on his comeback Bruno/Seldon, well maybe not they were both champions to be fair albeit cans who happened to have the belt but the fact is he lost every tough fight he had after he came out of prison.
I'm not saying the Tyson comparison is perfect, just better than one with Ali (which I think is pretty dumb frankly)