Either the German economy is grossly OVERVALUED or the Allied economies are grossly UNDERVALUED.
Using historical GDP figures for the start of the war (1938-39), based on Germany economy in WarPlan being 170 PP, the REAL values of the economics of the other powers should be ...
UK: Warplan, 80. Actual 135.
UK Colonies: Warplan, 0. Actual 135.
France: Warplan, 95. Actual, 90.
USA: Warplan, 230. Actual, 386.
USSR: Warplan, 250. Actual, 250.
Italy: Warplan, 65. Actual, 68.
UK Dominions: Actual, 55 (Canada only is represented, with 35).
By 1939 the German economy was flat out, with new armaments industries not coming on line till late 1943 or early 1944 ... there was no slack, not really.
The UK, French and Russian economies, however, WERE playing 'catch up' to a degree, but had been rearming since 1937.
I am not sure how to represent this ... if you could simply give the various undervalued economies their ACTUAL PP (which you cannot do) that would make things impossible for the Germans to work against ... TOO impossible to represent reality.
What I WOULD suggest is that the German economic increase percentage be reduced from the current 0.9% to 0% (no increase in arms factories till late 1943, remember, that's actual history!) until 1943 when it gradually starts to increase, either every quarter or every month, to 0.9% (historically, by that time all the increases were doing was barely keeping up with losses to the allies in the air and on the ground).
And give the UK a 0.95% increase from the get go.
The problem of then 'missing' 135 PPs from the UK Colonies is more vexed. You cannot create active nations in the game and inactive ones cannot have production of ANY PPs.
The obvious answer would be to create a 'UK Colonies' off map (one for Africa, one for Asia) and set up convoy routes to transport the PPs ... and start them off at a lower level than the straight conversion would suggest, but increase the base PPs every quarter or half year, but have a multiplier of only 0.5%, or less.
The USA is a bigger problem, especially if they enter early. They should only get 85% of their actual PP as 15% was allocated to the Pacific War for a start and, of course, they shouldn't get 100% of the remainder right away ... like the UK Colonies they probably should get a quarterly increase to Base PPs as well as a 0.95% PP growth rate.
The other possibility is to have variable unit costs for each nationality ... which IS possible ... and give them different factors ... so US and UK Armour or Mech would, for example, have a LOT more tanks, guns and artillery but use more Oil than a similar German unit (etc.)
It is a pity there is no way (at present) to change a Nation's PP in the Editor ... it really should be allowed ... and, as far as I can tell, there is, likewise, no way to increase Base PP output at any point during the game, or to increase the PP increase %age.
These are serious shortcomings ... for a non-RISK type game.
Author, Space Opera (FGU); RBB #1 (FASA); Road to Armageddon; Farm, Forge and Steam; Orbis Mundi; Displaced (PGD)