With the right people working with him it could take one off-season. Also, the adjustment(s) might not be as pronounced as we all think. It's where his swing, hips, head etc are at point of contact. Not that he doesn't need to go in the shop, but I've seen some weird initial stances at the plate that worked for people.
If his setup has looked like this throughout his pro career, and why it was left alone, I have no answer.