I think you are underestimated the value of a great athlete and too biased towards MMA/Fedor.
You do understand that Tyson could have been sick at almost any sport he wanted to do. Particularly boxing/wrestling
Fedor is tough and experienced as hell....but Tyson is 100x athlete he is. A prime tyson could have heavyweight champion wrestler if he wanted. I'm telling you dude...he would destroy him.
Yes, and you know that Tyson would have been able to train wrestling to a degree that a national Sambo champion and one of fastest, most experienced and explosive MMA grapplers would not be able to take him down? I'd like to know how you came to that conclusion.
Just because he was great at boxing does not mean he would be great at wrestling. Cro Cop was one of the best strikers in MMA and was good in K-1, yet his BJJ wasn't/isn't that good. Schilt is a great striker and look at his TDD/MMA record.
You can have as many "what if" situations you can think of, the fact is, Fedor is a monster MMA HW who is very fast, explosive, and is a Sambo national champion many times over, where as Tyson is a great boxer and just because he's great at boxing, does not mean he will be great at wrestling or any other physical sport, no matter how good of an athlete he is.
It takes more than just being a good athlete to do well in things like wrestling, and just because Tyson was a great boxer, does not mean he would have the skill to be a great wrestler(which he would have to be to stop Fedor's takedowns).