Nobody has perfect mechanics. In fact I don't believe there is any such thing in reality.
Stange stance, strange stroke, strange shot choice, strange strategy.
Sure, if teaching or learning the fundamentals are important. Same with a coach fixing a problem in an advanced champion player. The coach is an advanced player. They know the ideal fundamentals, demonstrate them, and teach them.
I think this is part of what makes it all interesting, similar to other sports.
Champion golfers, tennis players, pitchers, quarterbacks, and more have quirks. Sometimes the quirks of a pro become a standard method.
In the end, no matter what, each is an individual player and there will be individual variations. Sometimes we think someone reaches excellence in spite of the quirks. I think sometimes we have to consider they achieved it because of those quirks.
Learn and train the best you can at the fundamentals, but play your own game. Be you.