[Yoda]

so the left arm is just stretched like a sail on a sailboat and hangs on for the ride. correct?

and the extensor action does not power the backstroke, that would be the bending of right elbows job while the right forearm keeps the sail geometrically correct and constant? would that be a good way to view?

i've always kinda tried to stretch out with right forearm going up, you know kinda pushing it out out out, not really seeing this as the right elbows job. interesting.

That's the way it works, Powerdraw. You've got it now. Stay with it!