There are two types of management, managing for a field you’re familiar with, and managing for a field you’re not.
In the case of managing for a field you’re familiar with, you’re going to leverage a lot of your experience and expertise to make decisions.
In the case of managing for a field you’re not familiar with, you are going to rely on your people assessment skill, your surveying skill, and intuition. Do note, that if you’re going to hire someone to be an expert in the field, and constantly doubting his work, then you need to one, either hire a new person, get some training in the field so you can ascertain whether or not doing his job properly (but then you’ll be micromanaging; doing your job and their job), and finally you can keep your ears open to see if there are disagreements with the approach.
It’s important to realize what type of management the organization hired you for, so you know if you’re managing the way they expect you to. In a way, we’re all cogs in a larger machine, if we’re fulfilling our purpose, things will run smoothly, if we’re not, there are going to be hiccups.