In most large organizations, like GE, engineering managers may be put in charge of a variety of operations. Once you are promoted for the second time you find yourself managing some unfamiliar work. Your first promotion was to be manager of the group you worked in and helped build. You were, therefore, quite knowledgeable of the work and the people.
The next promotion would be to manage about seven such groups, almost always including the one you just ran. The other groups were doing work you were aware of but certainly not an expert in. You would have to learn each group’s work as best you could and, most importantly, determine the real technical leaders of the work, probably but not always, including the manager, and rely on their ideas and suggestions.
In the aerospace industry at GE our major customer was the US Government which often was a “moving target” in that they had uncertain/changeable budgets which sometimes had us in whiplash from stops, starts, sudden budget changes, etc. As a result many reorganizations occurred in our divisions resulting in layoffs and hiring, sometimes at the same time because a new contract may need “brain surgeons” while we had too many “plastic surgeons”.