I have come to believe that the majority of modern day golf instruction is based primarily around instructor style preference. Jim Hardy has his own swing style, the One-Plane Swing, as do Bennett and Plummer with their Stack and Tilt. These teachers and others have studied the swing and come up with their own interpretation of how it should look, yet too much of the information peddled today is form-based rather than function-based.
In studying the top golfers of all time, no two swings are alike. Who is to say that Ben Hogan’s flat plane is better than Jack Nicklaus’ vertical arm move? Who is to say that Sam Snead’s slight over-the-top move was better than Nick Price’s drop-down transition?