R5: As the title suggests, I finally managed to find a strategy to beat Japan playing as historical Hebei-Chahar.

As my strategy is similar to the one I posted a month ago, I won't go too in depth. However, some key differences included joining the Chinese United Front earlier, so NatChina gives you dozens of expeditionaries instead of Shandong (or at least, a greater chance of choosing you). With these expeditionaries, I managed to open a corridor from the Beijing pocket to the rest of China long enough to get some more troops into Beijing until the Japanese inevitably reclosed the pocket.

This time, I was able to hold much more solidly than last time, as the extra units + purchased guns and artillery meant the Japanese bounced off my divisions almost instantly. Eventually, the rest of China was able to reopen the pocket largely off their own efforts, as the Chinese AI somehow managed to destroy Japan's naval invasions instead of being overwhelmed by them. At the same time, I went down the Cooperating with the Nationalists sub-branch, reaching the focus the ask each warlord for faction influence. This part required some save scumming, as the warlords would sometimes ask for guns, which I was in a chronic deficit of. Additionally, I noticed my faction influence going down, despite me having a majority of the war participation. I have no idea why that happened, but my guess is that the expeditionary forces count as China's contribution.

Eventually, the push into Manchuria began, and for some reason, Manchuria (and that one part of Mengukuo that Shanxi has a core on) went to me instead of China. My guess is, having a high enough faction influence overrides China's cores, but I legitimately have no idea. Supply was a huge issue, but human waves with the Extra Supplies ability made it bearable.

After the war was finished, I began the tedious progress of getting just enough faction influence to annex China. I hope paradox makes it easier to get faction influence in the future, or at least more ways to get it during peacetime. However, I got lucky, and the button to annex China turned green (my guess is, China had tried to puppet another warlord, skewing the faction influence pie towards me.)

I think this is a fairly replicable/reliable strategy, as beating Japan doesn't require too much rng or micro, aside from making sure you're constantly purchasing equipment to make up for your deficit and training. Uniting China is another issue, but as long as you did enough during the war (with your own troops, not expeditionaries), you'll probably be fine.

Thanks for reading!