I would hazard a guess that if you took any event, athlete, celebrity, statesman, Blah, blah, blah, and gave 6 " historians " a commission to write about them, each would have a different perspective on the subject. So I wouldn't take them too seriously if I were you.
John L Sullivan picked Johnson to beat Jeffries 2 years before he did, he said in March 1911,Sam Langford had no chance to beat Johnson."Sam Langford is too small to ever expect to cope successfully with a man of Jack Johnson's size and skill.No little man is ever going to whip Johnson,"Sullivan said Langford was wonderfully strong,but it would take a big man, at least as big as Johnson,and a clever one with a terrific punch in either hand to whip Johnson." I don't think he is in sight just now". Sam McVey said that if Langford was the same size as himself or Johnson ,neither of them would be able to beat him, but that he would not beat Johnson ,saying Johnson had never suffered much punishment ,for he blocked or eluded all of the punishing blows.McVey said Langford was a dangerous hard hitter who could take punishment,but was handicapped by being small,and was not the cleverest. This was September 1911. Adam's new book is choc full of these quotes. Charley Rose had Johnson at no 2. he made his picks in1968 ,he did not rank Ali in his top ten.
That depends on the historian. If there is no film, then you have to lean a bit a historians input and balance it with the film you have seen in fighter XYZs time. Rose felt Sam McVey was better than Liston, Frazier and Ali. No other historian alive or one that lived to see them in the in the 1960s agrees with Rose. There is clear film on Sam McVey. Hes strong, but a little gun shy, a bit of a one armed attacker with his left, and not very skilled by the standards of others who were filmed in his time.
Sam McVey was famous for being able to absorb an inhuman amount of punishment two of his most celebrated fights ,his third and final bout against Jack Johnson and his Paris fight with Joe Jeannette amply demonstrate this. imo Gunshy is the last sobriquet that should be hung on Sam Mcvey . Jack Johnson always said he was the toughest of his black contemporaries and he never changed that opinion even after he was long retired. Charley Rose's list is as follows. 1.Langford 2.Johnson 3.Dempsey 4.Louis 5.Jeffries 6.Tunney 7.Dempsey 8.McVey 9.Corbett 10.Baer No Frazier? It should be remembered that that list was compiled in1968,2 years before Frazier beat Ellis for the recognized crown. Nat Fleischer did not have McVey in his top ten but he did have Langford and neither Ali or Frazier. 1.Johnson 2.Jeffries 3.Fitzsimmons 4.Dempsey 5.Corbett 6.Louis 7.Langford 8.Tunney 9.Schmeling 10.Marciano Fleischer's list was compiled in 1971.