No.
I'm saying that no Japanese player should be able to fill out TOE's faster, build more than historic number of aircraft and expedite CV production to mid 43 all at the same time. (maybe one of the 3, but not all 3 at once.)
I have not seen one AAR where the Japanese player complains that they are stretched too thin with supplies, Fuel or HI capacity. Of course, I don't read all that many AAR's, so my POV may not be an accurate one. And, I mean really constrained. Hisorically, Japanese fleet options were constrained considerably by lack of fuel. I just don't see that anywhere. Too much fuel. Probably too much supply. And I also have a hunch that there is too much HI at game start. Again, I don't think you should weigh my thoughts too much. It would be nice to see a competent person actually analyze Japanese production to see if it seems historical. (I know that is a major, major undertaking though.)
I am an economic gamer - and I design and run production games and production sections of games. In my very first WITP game I ran Japan into the ground in 7 DAYS - ran her out of BOTH supply and fuel. It is just a question of the tempo of operations.
On the other hand, resources were not constrained enough. I was able to balance oil imports and exports in about a week - nonsense. But I clearly established "don't expand everything at once or NOTHING will expand because you ran below critical supply levels." So there ARE limits.
Historically, the most critical war resource, sans oil, for BOTH Japan and the USA was steel. Steel is used to make factories, trucks, battleships, railroads, you name it. But you only have so much steel each month, and it is not a number you can quickly change very much. Making one battleship means you used the steel for 150 escorts or 1500 tanks - a real world example. WITPs system does not make it easy to see this because it is a bit too abstract - steel is more or less MFG points - or in them - but it is soft because other things are in them too. And there is no need to import coal and iron ore from Manchuriato make steel - ANY resource point from ANYWHERE will do.
The biggest reform for WITP needs to deal with code: get rid of, or reduce significantly, supply points from resource centers. We can add local industry - and should - which can make local supply points in limited amounts. But right now the large amount of supply from some resource centers is ahistorical, and kills the need for shipping.
The second biggest reform for WITP we CAN do - get rid of those almost nuclear powered ships. There are data field errors (fuel values in the range field) and just plain wrong range values - and massive (but simple) data entry will fix that. Then you won't be able to move too far without refueling. And the fuel needs will be much greater - because most ships UNDERSTATE them.
I do not know how to get Matrix to fix the supply from resources problem? The best way is to form a consensus and ask and ask and ask.