Ok, I tossed a crappy image together really fast.
The size is crap, I had to zoom it in. But it is akin to what I use to run C&C: Red Alert on with my crap PC long ago. And remember, the actual system is a bit bigger.
All the controls are on the bottom. I figure, if you hold down a shoulder button, the bottom screen will reflect the same image as the top screen, allowing you to select the troops needed. A real quick select and drop. When you let go, the screen returns to normal. Showing the map, the the controls, and what not. The 4 button interface on the front right is your map scroll controls. Allowing you to zoom around the map at will. The system might be a bit akward at first. But I believe it would become easier then the mouse system we use now. You will just lack the quick keys.