I doubt Tyson would be as far down the list as you think. He was masterfully prepped for his early bouts. I would be he'd be more successful against some of the earlier boxers than you think.
That is, "I would BET." Sorry.
Tyson in his prime relied mainly on intimidation to win his fights, and none of the fighters on my list would be intimidated in the slightest. Also, if this hypothetical round robin tournament happened as I described, his mental state would be pathetic by about his 3rd or 4th fight (after getting beat badly once or twice), and he'd quickly be reduced to his ear-munching self as a result.
The guys who would finish at or near the top of such a competition would have mental toughness in spades, and Tyson just doesn't cut it.