I'm not sure what the best behind-the-back animation is. Curry's is the fastest in execution and to shoot after the dribble, but the one that causes the least separation for the opponent. I think Harden's execution of the movement is slower and it takes a while to animate the shot following the dribble. But it causes an absurd separation both laterally and backwards in relation to the opponent. As for J Murray, I feel like it's the middle ground between the two (Curry and Harden). I'm currently trying Murray's.