If you are going to go KJF, you have to do it full-bore.
If you divert major resources to the Pacific, then the US is going to be weak or non-existent against Germany. That means that the US has to make PROGRESS and ADVANCE against Japan… and QUICKLY.
A few super subs, 2-3 turns into the game is not making progress against Japan. It is sending IPC’s into the water to be sunk.
You can HARASS japan with your intial forces in the Pacific. You can even build an IC in Sinkiang for FIGs and ARM, which, once Japan gets too strong for those forces to successfully harass, can be evacuated to Moscow to aid in defense. But anything more than that, and your harassment of Japan simply means a lot of dead US IPC’s in the form of sunk navy. And it leaves UK to try to build up a fleet to survive/defeat the Kreigsmarine w/o assistance, and that takes a few turns to accomplish… around UK 3 or UK 4 the UK will be ready to start landings… if any TRN’s survive the attack and counter-attack of the Luftwafe and Baltic Fleet.
Meanwhile, Germany has raided 9+ IPC from UK in Africa and pushed Russia back to be trading Caucues. Germany is in the mid 50 IPC range by about G4, while UK is just begining to make landings… assumign they did well on the naval battles and don;t have to rebuild all of their trannies, and UK is reduced to just INF for 4 TRNs, because that is all they can afford. And it will take a few turns for them to get enough INF in position to do much against Germany…
If you are going to KJF, do it right. Spend the $ on surface ships and TRNs by the US in the Pacific.
Have Russia divert AT LEAST all eastern INF, plus a couple of ARM, and even 1 or 2 of their FIGs for battle in Asia.
UK will need to just realize that Africa belongs to Germany for a while, and go after FIC and anythign else they can get to (which may be some islands if they were able to preserve any of their fleet).
And while doing that, get every INF and FIG into Europe you can to try to keep Germany from taking and holding Caucuses, WR, Karelia and Archangel…