In some sports, a certain head position is considered desirable, although it may be the horse is supposed to want it there. Certainly there are indications that riders will work to place it there, for whatever reason.
But outside an arena, the horse should be looking where it is going, and how far out it needs to look is determined by speed and the condition of the ground - or how far away a jump or cow or something it needs to know about is.
Some horse sports HATE initiative in a horse. Others value it. My point was that when I neck rein, I have no interest in the position of the horse's legs at the time I move the rein. If it is off by 0.5 seconds, so what? The horse understands what WE are doing, and will take care of his side.
From the link I posted:
"The preparatory command explains what the movement will be. Military Training Instructors often call this the thinking command. It allows the individual performing the drill movement to form a mental picture in their mind of the movement that is about to take place."