Abe Simon was 6'4 255 pounds and had good fundamentals, an iron chin, great strength and fought in a superior era to AJ's era. I think he beats AJ.
Let's break it down. Abe Simon- 6'4", 82" reach, and over 250 Lbs. 36-10-1 (25) overall and 0-2 in HW World Title Fights. He was stopped 4 times, twice by Joe Louis. He beat no one worth mentioning but he lost to Lou Nova, Buddy Baer (by KO), Lem Franklin x2 (once by KO), and others. Joe Louis beat him in 1941, KO13 and 1942, KO6. Abe was down so many times by the Louis in these two fights that I lost count. Louis was a couple of inches shorter, with a 6" shorter reach, and was outweighed by 50 Lbs. Anthony Joshua is a quite the specimen at 6'6", an 82" reach, and about 250 ripped Lbs. 23-1 (22) overall and 8-1 (6) in HW World Title fights, he is a 2x Champ. He was stopped once but also avenged that loss. He beat D.W C. Martin, D. Breazelle, E. Molina, W. Klitschko, C. Takam, and A. Povetkin by KO. He beat J. Parker and A. Ruiz by decision. His only loss was a KO dedeat to Ruiz. Anyway, Simon wouldn't have much of a chance vs. Joshua.
That might be so but those guys he lost to were stiff opposition that may have beaten Anthony Joshua. They had to be amazing fighters to beat Abe Simon. That just reinforces how strong that era was.
**** the stats, just look at the way the dude fought. No head movement at all. No wonder 200lb guys were able to KO him. They just kept punching him at will. All he had was size and the abilty to pressure(due to his size). However against smarter foes, that pressure was easily turned against him. Good luck walking into Anthony Joshua´s shots.
It's just that those guys were so good, they were able to beat Abe Simon. Abe Simon was a monster and so you had to be super skilled to beat him. AJ may not be able to get past this skilled giant.