In his DVD, Hebron a GSED, states Percy's book as one of his major influences. Hebron states the three parts of the swing as momentum on the backswing,gravity to start the downswing, finally rotation. Momentum is the heave you are talking about. Doesn't ring a bell in strict TGM terms. SHoulder turn takeaway with bending of the right elbow and extensor action sounds right. Hands and feet don't move themselves: they are moved. Chuck Evans describes a similar backswing in his Ebook.