I am interested in this as well.
We are looking at going from AGOL to ArcEnterprise. I have done research into every possible solution, I know how many users we will have and what their roles will be. With that said, I can never seem to get a real world outline of what we truly need or what someone else uses. I feel like it is a guessing game when it shouldn't be.
Our company doesn't need much, just the bare minimums but nobody can show me what that looks like. I am hoping someone here can outline what they use.