Dear downvoters: how do you satisfy when 200 units irregular army, 10 SoL, most of it's profit goes to Britain, British's mandate colony india is the 2nd great power of the world?
Subjects probably should take a prestige hit preventing them from becoming great powers and foreign investments maybe should generate more prestige for the owners. But to be honest, India had a giant economy regardless of profit, sol, or military and probably should have a reasonably high rank in most games. It was the jewel of the British empire for a reason. Also I’m not sure GNP would fix your problem.