I think your China rule does more good than harm, especially when combined with an A0 turn and/or starting factory in sinking.
It could be fun to try a game with:A0 noncombat Impassable Gobi Desert, and One free extra starting factory in a 1-IPC territory for each player.
I think those rules would all synergize well with each other!
One of the things I find interesting about this potential change (closing the western border of China) is that it makes the Soviet Far East more defensible for Russia. If Japan pushes along this route they have to come heavy or risk being stalled up at the Yakut/Evenki choke point. The Russian supply line to Evenki has a one move/turn advantage over Japan’s out of sz 62/Manchuria. So even though Russia clearly has less purchasing power and hitpoints to send east, at least their final defensive line is closer to reinforce. Meanwhile if Japan goes north with the plan to march “all the way” then this takes pressure off India. China, if it had a little bit more to work with at the start, would then be a serious potential distraction. Also because the Indian units no longer have to worry as much about the Russian center (at least not compared to OOB with the Kazakh choke point) I think this makes them somewhat more likely to engage Japan on the offensive.
If Japan goes south to India, then it might be possible (depending on the presence of the USN) to reinforce the Russian position in the north. So you have a kind of counter weight, to the South Pacific. Again China would function as a stall, since every round Japan commits to China puts them likely one more turn off India. I think if the US had a reason to stay, more units for a mini stack (like they can achieve A0) or an IC, then they’d be more likely to keep the Flying Tiger around.
None of this really requires new mechanics or anything special.
It uses the regular rules, and standard set up cards.
The change is just to turn order, and enforcing a movement restriction at 2 tiles (one that applies to all units/players equally), the same way you can with sz16 if the bosphorus is closed. I think the 1 ipc factory idea would be fun. But perhaps it’s not even necessary if America had a viable purchase on A0, or just enough surviving starting units to have an impact. Either way I think China would feel more like the situation in WW2.
The change reflects what CWOMarc has mentioned in the past that the map doesn’t really present the vast Chinese interior with appropriate geographical scale. This rule (closing the Chinese border with Russia) is a way to abstract that, at least for gameplay. The terrain here is imagined as unforgiving, without the roads and railways and airfields or what have you, necessary for moving a huge army across it. Consider this movement restriction to reflect the Taklamakan desert, the Tibetan Plateau, or whatever other geographical justification is required. Szechuan is no where near Kazakh in the real world, and Sinkiang is pretty damn far from Evenki too, so this rule just puts that geography to scale. Basically “too damned far” for practical movement, and treated like Himalaya, or Mongolia (which in 1942 is imagined to include the Gobi). Here the rule is the basically like saying that for logistical purposes, this part of China didn’t look much different in 1942 than it did in the days of Genghis Khan, and harsh enough to be treated like other geographical impassable territories. Mostly for gameplay purposes, but it has a justification in history and in reality too.
In tripleA terms the rule to close the border between Russian and Chinese starting territories doesn’t even require a gamefile edit. You can option the rule on a game by game basis as desired. Player enforced, just like sz 16, and stated at the outset.
Ps. I think such a rule would make it at least somewhat more difficult for the Japanese to send fighter support to Germany. With the Chinese border closed Japan can’t send fighters from Kwangtung to Ukraine with such ease. Now those same fighters would have to travel across the Northern Route or the Southern Route or be launch from carriers towards Europe. I don’t doubt that crafty players will still find a way to get their fighters around the map, but at least it won’t be such a straight shot across central Asia, as it is OOB. I think this Japanese fighter transit is actually one of the top 10 problems, so anything to reduce its immediate effectiveness probably helps.