[Yoda]

If one does not shift weight to lead foot at beginning of downswing, it seems to me, they would spin out rather than pivot.

The Hip Shift is the Weight Shift.

When the Weight shifts, the Hip Shifts.

When the Hip Shifts, the Spine -- the Axis for the Shoulder Turn -- Tilts (lower portion toward the Target / upper portion fixed by the Stationary Head). This enables the Right Shoulder to thrust and support the Hands directly toward the Ball. Now . . .

The Hands, in full command of the Hands-Controlled Pivot, can aim their Straight Line Thrust toward the Ball.

Drill: From the Top of the Backstroke, throw a golf ball at a golf ball on the ground. Clear the Right Hip, then . . . Straight Line Thrust toward the Ball. No matter the actual Path of the Hands -- Straight Line or Circle -- that's the idea.