Let him know he should not let perfect be the enemy of good.

Let him know he should not let perfect be the enemy of good. It’s possible he wants to go above and beyond and doesn’t understand how his work fits into the big picture. Try to provide context for the ask, let him know who’s reviewed the document so far, who will review it after him, and why it needs to be done a certain way. Help him learn the why behind the work instead of doling out tasks. If he’s a newer employee try to be a bit more patient so he learns your preferred way of working as a manager. I’m confident that he will adapt his methods in time but he might have come from a role where other managers encouraged him to be innovative and really show he can move the needle. If he is working for other managers at the same time as you they might also have very different expectations happening simultaneously. Good luck.