For everything the catchment size will be a little different. Basic health services might be smaller, specialities slightly larger. Education likely to be very small (neighborhood level). There are likely to be very high level agreements on basic stuff like, "Don't dump toxic waste in the river" and high level arbitration mechanisms to deal with that. But those don't have to be government run. In fact, the whole reason that many companies choose Delaware for incorporation is that they have their own system of chancery courts that make it faster, cheaper, and easier to settle disputes. The logical fallacy in your thinking is that people look up the ladder right now because that's what we've been trained to do. There's no reason that this is the natural state of things. Giant nation states are a remnant of colonialism and imperialism. We have decentralized planetary light speed communications and decentralized planetary light speed money now. People are far more self-organizing and cooperative than you're giving them credit for here. Don't fall into the Hobbesian "Nasty, brutish, and short" trap.