>>103243655>>103244555Don't know about now but 60s kingpin is literally just a giant with short shins. He's like Andre the giant but with shorter legs and even larger hands.
His physical strength goes far beyond a giant's, of course, but you can easily explain this in the marvel universe.
Strong, clever, brutalized man goes to prison and discovers that being strong, clever and brutal is a pathway to success in the underworld. In a comicbook universe, it would then be silly not to experiment with superhuman serums and whatnot to further improve your standing.
This is doubly true for a giant, as giants bodies deteriorate faster.
In the ultimate universe, fisk took something to increase his strength and intelligence, but I can't remember if it was the hulk serum or the oz serum or the supersoldier serum. It's not out of the question for 616 to have dosed himself with something to improve his strength.