Player armour stands (for Custom NPCs)

My idea is that when an armour stand is sneak-right clicked with a player head it changes to that players skin while still having all its armour slots empty. Or when summoned with the "/summon" command the NBT would have a new tag specifying which player's skin it would have or (maybe) allowing to specify the location of a skin on the computer to allow for even more customisation.

This would greatly simplify the creation of custom NPCs for mapmakers.