He played one role: John Wayne. And as to his being a great man, not in my book. Not someone who was pleased to be in the situations where all that was fired were blanks, but not in a situation where real bullets were fired. I have reference to the stories of how he avoided service in WWII.
Perhaps you would like to tell that I'm full of it and he really wanted to serve but couldn't.
He was just starting out in film when WW II broke out and he did take the opportunity to duck enlistment.
He did, however, serve in many other ways, raising morale like few others could. Not every man can be a Jimmy Stewart or Clark Gable (both served in uniform.)