Compared to the mental control that high-level zombies have over low-level zombies, high-level wills can control a broader range of zombies, but it isn't as satisfying as mental control.
Simply put, the will of high-level zombies is just the unconscious overflow of their brainwaves, which then influences the surrounding low-level zombies. This is a one-way control, like having a toy car that you can only push forward from behind; within the rules of the game, you can't stand in front of it and make it go backward. If you did try to make it go backward from the front, that would be the mental control that high-level zombies exert over the evolutionary path of low-level zombies.
