How can you have Foreman over Holmes in a head to head list? You could easily out box him. Liston at 2? Tyson at 4? Sure in his prime he ranks high head to head, but 4 is a bit high IMO.
IMO no one would beat him 10/10, or even more than 6/10. A fight with Ali would be real close, and same with one with Marciano.