Have you ever considered why golfers do not setup like Diane in 10-6-B?
Note that her right upper arm is along/parallel to the TSP. I think that it is biomechanically very difficult to fold the right elbow to achieve the desired right forearm flying wedge position with the hands behind the right shoulder at the end of the backswing - when starting with the right upper arm in that position. It is much easier when the right upper arm hangs down vertically - as in 10-6-A.
You used the word "desirable" with respect to the TSP. In what sense is the TSP desirable? Is it from the backswing and/or downswing perspective? Is it from a end-backswing or impact perspective?
Jeff.
Try to setup like 10-6-b #1 and see how natural, relaxed and comfortable you feel.
Desirable = 12-1-0 and 12-2-0.