@CrazyG @Schulz Well, of course, it is virtually impossible for wars to be well balanced, as that would be an exceptional coincidence. It is well known that WW1 was greatly unbalanced in favour of the Allies, and just the great effectiveness of defence kept it going for so long, after the first shot at rapidly taking Paris failed. The main rebalancing element would be the political/moral fragility of Russia, but I'm not even sure that can be decently represented under the current constraints of the TripleA engine (I would think like accounting Russian TUV losses, then an increasing chance of collapsing after they are above a level). Also the Germans could have had a much better shot at the west if they were not so greedy in wanting to have territorial gains in Russia, but would have accepted a separate peace or armistice at the current borders (or maybe only demanding the Kingdom of Poland).
The other element is that you can sum the rich Belgium to Germany. You cannot sensibly do the same with the Netherlands, because they have colonial territories about as much as valuable, so you would not take their homeland just to gift your opponent a same or bigger value of territories (if the territories outside the scenario are not represented in any ways (convoy zones?), the Netherlands can be impassable).
Maybe WW1 would have been fairly balanced if Italy would have fought on the side of the Alliance (it was actually part of).
Instead of representing the US Americans, you can have some Allies victory condition that would represent the joining, very late, of the US America, and simply tell the players that, at this point, the Alliance is doomed and the Entente wins the game (kinda like the multiple victory options of Civil War). I believe this would be totally fine, as when the US Americans joined Germany would have lost for sure, even if they hoped to still have any chance (at those times not everyone was well aware of the actual power of this ex colony, not even the taking of Paris could have offset).
In my opinion, the biggest inconsistency in WW1 maps is that they tend to make the Ottomans way too strong or, anyways, not weak enough, maybe also because of the Gallipoli debacle. Whatever the metre, the Ottomans in WW1 were less than 1/10 the power of Germany. On the other hand, Germany can be able to give PUs to the Ottomans, if they want.