Victory in the Pacific is essentially impossible if you lose China. You need the cash from those territories to be able to to outspend India + ANZAC + US in the theater. Still, I find if China is making 15 PUs, ANZAC is at 20, and India can get up to 10, it is difficult to make much progress anyway. There will be more Allied ground units made each round in Asia than you can pump out from 2 factories. It is possible to build a third Japanese factory on the mainland, but then you are spending almost your entire budget on ground units and can’t compete in the naval battles.
When Yunnan is held strongly, I transition to helping Germany out by forcing the US to keep spending in the Pacific. It is a huge help if you can hold the Philippines, threaten Hawaii, sometimes take the Aleutians or an ANZAC territory, and prevent India from sending troops West. You can still make 40 PUs without much of China, convoy raid India to keep their economy slow, and force the US to spend 20 PUs a round in the Pacific to prevent things from getting too out of hand.
