Here what I do
From 1936 Japan builds 2x15 infantries and the rest of the IC goes to Factories.
From January 2nd 1936 Japan Trades:
Receives ALL of Netherlands supplies production at 90% Chance.
Trades supplies for resources with EVERY Country in the American Continent to improve relationships with them.(1 supply with whatever it can buy)
If Germany was unlucky with Trading and cannot support Japan, Japan must forget some of its Trades But MUST make trades with resources producing countries such as Brazil,Chile,Peru,CANADA,MEXICO.
Does NOT produces any supplies for a year.
It is assumed that Germany supperior trade earns enough to support Japan for 36 (and Italy for that matter... and of cource Germany itself.... NO Axis country produces supplies)
From 37 and on Japan produces some supplies and by November 37 must have knocked out of the game at least 24 chinese land divisions and have Nankin surrounded but NOT captured.
When the 2x15 Infanty finishes the spare IC goes to what else more factories...
By May 39 a series of factories ends and ALL of Japans production goes to supplies that are send to Germany.(Japan uses the +20% supploes minister)
Germany receives about 70.000 to 100.000 supplies from Japan until the war starts.(Perhaps more which careful micromanagment)
Once war starts All trades with Germany get canceled... untill Germany and Japan are able to trade to 100% efficiency.(supposely when they share a common border in central Asia)
By January 1st 1942. Japan has:
220+ Base IC.(perhaps far less if Japan has done poor resourse Trading)
8 '41 Carriers with unbrigaded '41 destoyers to screen them. 8x more in Production.
20-24 '38 CAs with '41 destroyers to screen them.(this destroyers have '40FX brigade on them thus giving them the same firing range with the CAs. 8-10 x more in production.
2 CLVs 2xmore in production.(about to became 4)
110 '40 Interceptors. 10x more in production.
Has air bases (3 lvl3) in importand Japanese islands in the pacific.
And of course has puppeted China.
Thats my Japan.
Thats the SPARTAN Japan.
People call us cheaters for achiving that....
Is your Japan remotly close to this?