Mine? Charles, Frazier, Patterson, Holyfield. That order, with a footnote to Jerry Quarry and George Chuvalo. As a top 4, I have it clearly Ali, Louis, Lewis then Holmes.
You would have to make the trademark landmark look the part with guys of history and some lore all from the U.S if it’s Mt. Rushmore as it’s a United States thing. John L Sullivan Ali Louis Marciano Would do the trick and in today’s world certain groups on either sides can’t complain ,keep it one weight class and there’s no crying over race issues . If I had to do a bizarro one and was evil and wanted the craziest guys and can transform Mt. Rushmore like In Superman 2 . Butter Bean Tony Galento Mike Tyson Tyson Fury
Fury deserves to take up all 4 spots on the mount. Because defeating an old Wlad then ducking the rematch for 3 years. Returning only after Wlad was well retired. Fighting to a draw in which he almost got knocked out and winning the rematch against a one armed limited Wilder is far better than all heavyweight greats that came before him.