California would be far better breaking off from the rest of the US and becoming their own sovereign state. California’s incredible potential is being completely stymied by the backward policies and red tape of the US. It’s way easier for smaller states to more effectively cater to their people.
China and India definitely need to take this into account. There’s a reason why mammals eventually outlasted the giant, lumbering dinosaurs. Guangdong is also a region that would be better off doing its own thing rather than being held back by the dictates of a city far, far away.
Thus, I’d say a better idea than splitting California into six states is having California become its own country with 6 provinces/territories.