For min/max would you not want 3 expos -- like any Tradition play? It took me longer than average to figure out, but definitely Trade Missions >> puppets. Still, you really want two or three cargo ships feeding the cap.
The part I struggle with is figuring out which sort of CS are the most disposable. That is, which CS type are the least bad to puppet as opposed to having as an ally?
Being within range for early cargo ship is the main criteria, but usually there are some choices to make. Mercantile, Cultural, and Maritime are all so valuable as allies, that I kind of settle on Religious and Military as the better options.