Mutual attacks - where do they fight?

[Tris]

I'm unaware of any historical precedent for a conflict in which commanders felt they were able to have one main force, without patrols and pickets, and got away with it.

As for gameplay, I don't know if this would improve it. I believe it would make strategic movement and planning of campaigns more involved, and nations with strong LI but weak HI would feel very different to those in the reverse scenario.