This was actually done in the late 1960's using computer sims and films of mock fights between the contestants. The result was Marciano knocking out Ali in the final bout. Ali, himself, after filming the mock fights told of how frightening Marciano was in the ring.
What happened was that the mock punches started getting serious, and Marciano hit Ali on his arm. Ali couldn't lift that arm for days.
I think Tyson in his prime would have done well in that simulation. The problem with him was that his mental attitude cut that prime very short.
Marciano had stamina like nobody's business. .....non-stop punching until the job was done. That IS frightening, especially when combined with huge power and mental toughness.