great man theory is when you tell the story of a singular impactful historical figure

That actually is what great man theory is when it's presented in entertainment, especially if the ostensibly great man is presented as uniquely special in their role in a way that no one else could have done, or that their subordinates did not matter except as instruments that carry out the will of the great man.

From what I've read, the film does less of that overall than a typical Nolan film, but it doesn't mean that it isn't there.

It really is possible to enjoy a piece of entertainment without dogmatically rejecting criticism of it.