Layers are a function of size. Google doesn't have some magic managerial bullet. You either over-work middle managers with 1000+ reports and they have no idea what is going on (Google), or you have a structure.
Google are next, I thought you would see that when you link to an old post where Microsoft talk about being lean from your own post that talks about Google being lean
Yes, once you start to consider how many people one person can reasonably manage, then you realize the number of levels increases with workforce size.
Start with one person in charge of the company. Suppose he has ten assistants, and each of those assistants has ten managers they coordinate. Suppose the managers have ten employees each that they interact with, guide, and coordinate. So for a thousand-person workforce, the company has three layers of management in this model.
Google are next, I thought you would see that when you link to an old post where Microsoft talk about being lean from your own post that talks about Google being lean