@Arreghas I really love this idea!
One of the biggest problems I find in my games is stacking. Its not as fun when the game just comes down to two giant stacks on the western front, and the CPs can never win because they can never get enough guys there. However, I think this house rule combined with Economic and Political Collapse could fix that problem and give the game more of a trench warfare feel. Thank you for sharing and keep up the good work!