I find that M/WIF are pretty good simulations from an historical perspective, with one big exception: the war in China.
In most games, the Japanese player will empty most of Manchuria (especially the HQ) and will throw the 2 Marines units against China on the first turn in the early scenarios. This leads usually to a lot action in China and a real risk of defeat, and the need for China to have an economy that can keep up with the onslaught. But when the Japanese have their hands full with the Americans and the Commonwealth later on, with time China eventually build ARM, MECH, a full complement of planes, SUBS, and even CVs to reconquer China. All this is seriously off history.
Yet, all the setups in M/WIF (39, 40, 41, 42, 43, 44) have the Manchuria and Korea garrison forces on site, and the Marines anywhere but in China. The various setups are historical, and there are good reasons for them.
The Japanese High Command was absolutely terrified at the possibility of a Soviet invasion, and they had a substantive partisan insurgency to deal with in Manchuria. They would had never emptied Manchuria, historically. As well, the Japanese Army and Navy had serious rivalry issues, and never the Navy would have let its Marines forces to be used for “Army’s jobs” in China, except on the coasts.
Lastly, although there was a lot of civilian atrocities committed, the front in China was pretty static, with 3 exceptions: the summer 1940 offensive to capture Ichang, the spring of 1941 where the last coastal cities were taken, and operation Ichi-go in 1944. The Japanese Army had a lot of forces engaged in China, but by and large they were not doing much beyond dealing with partisans, except when it was given strategic priority in those 3 occasions.
So, to have a more historical war in China for MWIF, here is what I use, and the result creates conditions pretty to close the Japanese historical decision-making context.
1. Partisans option on (Japanese need to be serious about garrisoning)
2. No territorials (Japanese have to feel the stretch)
3. Forces in Manchuria and Korea cannot leave, until at war with the USSR, but units can be swapped once delivered in Manchuria/Korea: HQ for HQ, Army/Corps for Army/Corps
4. No warlords (tends to favor the Japanese against the Partisans; again they have to feel the stretch)
5. Japanese Marines can only be on coastal hexes, or a hex adjacent to a coastal hex (to ensure that Navy troops are not engaged in “Army’s jobs”)
6. Japan has to send one extra corps or army to Manchuria no later than J/F 41 (the Japanese worries were increasing as the global war was unfolding)
7. Japanese Strategic Bombing only available for Chungking, Chengtu, and Lanchow (this provides an extra incentive to take Ichang)
8. Chinese attack weakness option on (to keep the risks for Japan balanced)
9. Chinese production reduced to 4 build points, and it is a hard cap (that can be temporarily reduced by Strategic Bombing, and can be temporarily increased by Burma Road build points trade), with the cap increased by 1 more build point for controlling each of Canton and Shanghai (all this to avoid the completely unhistorical super mechanized Chinese Army of 1944 and 1945)
10. Burma Road can only send build points, or oil to save if the oil option is being used
11. Saving build points option on (to allow China to build more expansive units over time; and to keep the Japanese on their toes for the need of a potential operation Ichi-go in the later part of the war)
12. Unlimited divisional break down on (to allow for greater spread and flexibility for the Japanese forces)