It's for darn sure that Trump does not appoint an agency head to be the tail wagged by the dog, the agency being the dog. He definitely believes in hierarchal organization, and wants his agency heads to be in charge. And he definitely wants to be in charge of his agency heads. His antidote to this is that he is long reputed to be a good listener who takes advice. But he is clear that the role of the executor is to spearhead policy, make the critcal decisions after receiving research and advice, and see that they are carried out.
Trump is a real executive from the private sector. Produce or perish.