My (albeit limited) experience is that the company will become slightly more efficient short-term, but long term the bureaucracy closes ranks and goes into self

My (albeit limited) experience is that the company will become slightly more efficient short-term, but long term the bureaucracy closes ranks and goes into self-preservation mode which makes things even less efficient. Departments will start scheming ways to make themselves an artificial dependency on daily operations "You can't fire the [team], they handle approvals for [newly invented step in process]!" Pretty soon you have entire floors full of people who's entire full time job is essentially keeping their full time job. I'm inclined to think that once you're out of "startup mode" your company's efficiency will have more to do with its culture than its headcount.