It's like this: I'm a company commander. The president gives me, personally, direct orders to move my company into a position that isn't consistant with the battalion commander's plan. I ask if the battalion, brigade and division commanders are aware of these orders. I'm told that they are not. I'm under no legal, nor military obligation to follow such an order, without first insureing that my chain of command is aware of my change in battle position.
IOW, the president can't just do whatever the hell he wants and I don't care if the God in Chief.