After eating a bull, a mountain lion felt so good he started roaring until a hunter shot him. The moral: When you are full of bull, keep your mouth shut.
An expert at anything is very good at that thing. However, this does necessarily make the thing good. A person may be a master counterfeiter, but counterfeiting is a crime and the counterfeiter is a criminal. Bruce Lee was a superb athlete, a successful actor, and a master of his martial art, but that does necessarily make the martial art itself great and it does not mean that Lee’s philosophy was anything special. With his genetic makeup and his hard work ethic, he would have been great at any physical endeavor.
As I have said before, hand-to-hand fighting is simple; it has been around for hundreds of thousands of years—ever since two Homo sapiens decided they did not like each other. This is not quantum physics; it is just two humans fighting. No one is going to discover suddenly a new way for two humans to fight hand-to-hand that has not existed in the previous 250-thousand years.