We currently can specify `lowQty`for 0 difficulty and `highQty`for 5th, that assumes linear approximation of enemy count for other difficulties. I would like to suggest a new optional property 'medQty` that would specify Veteran difficulty enemy count, thus we could make nonlinear difficulty rise, with, for example, small grow on beginner-veteran and more rapid on experienced-superhuman. If not specified ('medQty` <= 0) we use vanilla logic.
To me, it looks like a tool to design a more precise balance for missions.