That great discoveries are so often made independently by multiple people when their time has come suggests that if the theory is right, Great Men are a dime a dozen.
Makes me wonder about Einstein. Were other people working on relativity too?
Essay: https://medium.com/cantors-paradise/einstein-and-hilberts-ra...
The only one of the three you name where you could make a case for them making a real difference would be Jobs (and I say that even though I am a non-fan).