Well, with a stock map you'd have asteroids and a lot of planets that you would normally be colonizing to remote mine if you want. Trade would help as well. But even without that you can support a lot of ships with ten good homeworlds. Especially without the cost of building and maintaining colony ships, and queue usage on all those little colonies that aren't really generating any income for you. At first your empire would be much stronger then you are used to. Of course the late game empires would be smaller than normal, but everybody would have the same handicap there. And less micromanagment.
