It’s been a while since I read it, but I thought the “actual” rule as articulated was. “Adding people increases communication overhead. At a certain point, more

It’s been a while since I read it, but I thought the “actual” rule as articulated was. “Adding people increases communication overhead. At a certain point, more people cannot increase speed but actually makes things slower”. Hence the more pithy “Adding people to a late project will make it later”. The assumption being that you’ve already maximised the number of people that could work on the thing (trying to get it out the door on time).