Yeah I have to agree with Keith (that's my middle name!). Unless you're expecting the neck to do all the work I don't think this would be the way to go. In most cases looking up involves both the head and the neck. Actually, as I try while I type I find it almost impossible to move just my neck back without moving my head.  That said, if the goal was to remove the sharp crease in the original rigging's backward motion, then I can understand . Just be sure to do as suggested and set realistic limits on the motion.

 

As for distribution, I don't see how you could do it. Unlike clothing, you'd have to also distribute the original mesh wouldn't you?