Technically speaking the CCP had actual fixed strongpoints & an HQ at Yan'an, which puts them a step above the truly province-less resistance movements, but we could simulate their popularity by giving them more partisans in the Japanese-occupied territories than the KMT.
If you want to take the KMT down an alternative path, go straight ahead - the entire point to Interactive History is that, although players start at a historic point in time with everything that's happened before said point already set in stone, you write your own futures Improving peasants' lives could be simulated by using $$$ to build up infrastructure instead of the army, for example. Though given the ongoing war with Japan that may prove to be easier said than done, but that's the way it should be
@IA For the sake of player convenience, in the event that you run out of fuel your fuel-consuming units will still be able to function, but will have to operate at a significant penalty in combat.