Corps is all about resources and number of cities. Many small cities 2 tiles apart makes it more profitable than big, spaced out cities. I had a game with cold, big, global highlands with many small tundracities and huge amount of resources. Mining inc gave 20+hammer/city and I produced more than the rest of the world. In cases like this founding mining inc is like reaching a victory kondition, its not even fun to finish game. SP is quite tilebased to build ws and wm. So when deciding corps vs SP evaluate your land for WS and WM vs amount of cities and corpresources. And dont forget citymaintenance.