Grant worked with Mike Perpich a Golf Magazine Top 100 Teacher as well. He worked with Mike right around the time he battled Tiger in the Canadian Open. Mike went to Mac O'grady with Jodie Mudd.
So Grant is definetley following the Morad system. He has a great understanding of the swing. He can definetely do different models. Hitting and Swinging. Snead and Trevino. Window 9 and 5.
I have heard stories from pretty reliable sources on his lack of confidence, which may affect his play. But he is very knowladgeable and anytime he speaks on the golf swing I listen!
Also in the sequence above I would note how similar Grant's set up is to Jodie Mudd's set up. Hands very close to body at address. Mac has also done this model.