Johnson is often criticised for fighting a lot of smaller men which he did. What is overlooked is that he also beat up a sh1t load of larger men. He probably beat more 200lb+ fighters than any champion pre Ali. I dont see why Simon, Baer, Bresica or Nova should necisarily cause him problems.
I counted 9 men on boxrec who weighed 200+ who Johnson fought. One of them was Jess Willard who beat Johnson, and a number of others who he fought late in his career. The rest were either under 200 Lbs or had no weight listed. I counted 19 men who Louis beat who were over 200 lbs, and he lost to none of them. Marciano fought 11 men who I counted who were over 200. Floyd Patterson had 14 fights against 200+ pounders. Liston fought 25. Thats a total of 4 men who I counted who faced more 200 pound fighters following Johnson and preceeding Ali. I didn't even try to count the numbers that say Braddock, Baer and some of the others had. Also, I realize boxrec is a bit incomplete. Perhaps you have a better source. I still think those guys were better men than the larger fiighters that Johnson beat, and what we need to look at, is the fact that the best fighters Johnson fought were not the bigger ones. Buddy Baer was a monster at 6'7", 240 Lbs. He had nearly as many first round KO's as Dempsey. I can't imagine Johnson getting away with the grabbing and holding style that he was so comfortable with against a man like Baer. Johnson also lacked power. Most of his wins involved wearing fighters down over a duration of time. Again, this would be a problem in an era of bigger and stronger heavyweights as his London prize tactics would not be as effective. I make no claims about who Johnson would or wouldn't beat, but I have serious doubts about him reigning for very long.
They were good enough relative to their day that they had no business loosing to a 53 year old former champion. I think we can safely asume that a prime Jack Johnson was an order of magnitude better than any contender in that era.
In terms of greatness, sure. In terms of head to head, who knows? Things had changed drastic. No longer were half of the contenders lightheavyweights or smaller, people threw combinations, worked on the outside, threw more jabs, kept the hands higher, etc.
Who were those contenders that he beat, then? You keep saying that, but everytime i watch footage of his or his opponents i see a totally different picture. Throw a punch, hold, wrestle, wrestle, attempt a few inside punches, break up and start all over again. No combinations, no work on the outside, no jabbing, gloves being kept at waist height.