Japan in a KGF situation can become nearly unstoppable if it is run with precision.
The goal is to go through Persia, as it is the key to unlocking Russia, it dominates the coast of Africa, and it stops any allied reinforcements from coming through the Middle East to Russia’s relief.
3 transports J1, IC in F Indo on J2, and an IC in India as soon as a sustainable 42 is reached. Sprinkle in 1-2 more transports, and somewhere between turn 5 and 7 (based on allies’ opening moves to slow Japan) the following Yellow Machine should be unveiled:
One transport in SZ60.
One transport in SZ61.
Two transports in SZ36.
One to two transports in SZ 34, along with the rest of the Japanese navy and between 2 and 4 fighters parked on carriers.
Each round 8 infantry are placed on Japan. Armor is placed in French Indo, the rest in India (as a general rule of thumb), as both builds will then be able to reach Persia on the following round.
The Japanese Machine operates like this:
Each round the single transports in SZ60 and SZ61 pick up 2 infantry each and drop them in F Indo. The two transports in F Indo split and go to SZ60 and SZ61, each picking up 2 infantry and dropping them in Buryatia and Manchuria, respectively. 3 units are built in F Indo, and 3 units are built in India. Repeat. Repeat. Repeat.
The reasoning is as follows- the northern backdoor of Russia is necessary to take for economic reasons, and to keep Russia from feeling comfortable. This can be accomplished with 2 infantry in an unending flow, supported by aircraft as necessary. If Russia/ allies make a push back at Japan in the north, no big deal- IPC values are low, and you just keep falling back toward your wheelhouse.
The central path through China is necessary to take for economic/ pressure producing reasons as well, but it is American economy, and if Russian troops are used to continually push in that direction, it is of little direct boon to Russia. The key again is a steady flow of infantry, 2-3 at a time from Manchuria and F Indo. Again, air power is used to continue to make small scale attacks in Evenki, Novo, and Kazahk.
The southern route is where the heavy lifting occurs. We all know how uncomfortable things become for Russia when Japan is rooted in Persia. It should be the single- minded goal, and should be there for the taking considering the air power and double Battleship bombardment capacity that Japan has at its disposal. Infantry/ artillery placed in India are backed up by armor placed in F Indo, with the whole structure underpinned by a steady, consistent flow of infantry over the top, through the middle, and more heavily through the southern path, all simultaneously. Russia will have its hands full.
Once Persia is taken and held, Japanese naval power can raid the coast of Africa, but it must be done with minimal troops, as the goal is Russia. Do not allow any allied reinforcements in that theater to distract you from the main goal, as Africa is a sideshow.
Eventually being rooted in Persia becomes an opportunity to become rooted in Kazahk, which means the Caucasus can be yours.
A quick review… 2 infantry per round over the north through Buryatia, 2-3 infantry per round up the gut via Manchuria/ F Indo, and 9-10 mixed units per round along the southern route through F Indo/ India and on into Persia. From there let your imagination do the rest.
The key to this strategy is Germany. If Germany plays it safe this will not work, as allied reinforcements will flow through Norway/ Karelia/ Archangel into Russia and do the bloody work in Russia’s place. Russia must be isolated, which means that Germany has to be super-aggressive in the following order- kill everything colored brown until allied landings force you to attack tan and green, and then kill as many forces as they hit the beaches as possible, so they never show up in Russia to help out against Japan. Leave France lightly defended, and invite Britain to engage in a trading war in France. The more allied units that die this way the better. If allied armies begin to stack, and pool, all bets are off.
It goes without saying that this is just a template and general strategy, and game realities can change things. But try it and see if you like it…