Here's the thing: The new arm action is a huge change. It was and is a big risk. It's not all that surprising that he's going to fight his command when he's revamped the most important part of his motion. Mix that with the fact he's always struggled with repeating himself, it's to be expected that the change to his motion might cause new problems with repeating his delivery. The hope, which I think is reasonable, is that this particular change will be more repeatable...but he has to get used to it first and he just hasn't had many reps.