Does team imply that they must be direct reports and not have a single layer of managers? With a single layer, each manager (including Forstall) would have just 34 people to manage directly. That's somewhat the same as a teacher handling a big high school class.
I bet they did. I bet there were times where he went directly to staff and said, "I want you to concentrate on this" or "Now refine this" -- "and then come show it to me."