besides Ali beat three top eight all-time fighters (Fraizer,Foreman,Liston) in a weight class? I don't see how some people don't have him as a top 5 fighter P4P
Not sure if I'd rank all 3 of those fighters in a top 8, but I'd say Greb achieved something similar by beating Tunney, Loughran, Tommy Gibbons, & Jack Dillon, & Harold Johnson did by beating Charles, Moore, & Bivins. I'd say you can find at least 5 fighters throughout history that have overall deeper/more extensive resumes &/or more individually impressive achievements. I'd personally rank SRR, Greb, Langford, Charles, Armstrong, & Walker higher.