That's one that I still sometimes struggle with as an engineer-turned-manager. The natural growth phase along this path is engineer to team lead, where you are probably still the most knowledgeable and where having the answers is workable and even desirable. The next step to leading a couple of related teams you can also usually get by by trying to have the answers. At some point right around there, it flips to where you know less than the people you lead and need to change your style as a result. I've seen a lot of people struggle with that (and I personally still occasionally struggle with it).