Ken, Bouldersdad, and Fourts... I understand that hitters that pull the front shoulder usually also pull their head, but what came first, pulling the head?... or pulling the shoulder? If you look at the two clips posted by FFS, they both start with their head looking over their front shoulders. At contact, their front shoulder has rotated out, but their heads are both still on the ball. In fact, as the swing continues to followthrough, they wind up with their head over their back shoulder.
The head follows the eyes, and the body follows the head. If you turn your head to look at something behind you, your shoulders will turn. If you are looking at something and you turn your shoulders, your head won't turn untill it is forced by not being able to rotate any further. Try it. Stand in the batters box and see how far you can rotate your shoulders before you can no longer keep your head on the ball.
I'm curious what your reasoning is.