What Gallaway talks about Will help a person improve over what he is currently doing...it's just that it might not do much for his mechanics...
I ran into to this way back in high school, when I first read psycocybernetics because there was a B.Hogan reference

I read inner game of tennis before the golf book came out and still have the golf...and I think I played about as well as my technique would allow (had a long loose swing)...recalling 'the feel' was the hardest part for me, not enough of that talent LOFT...
We all agree that the mental is necessary to take it to the next level...takes two to tango LOL