For just military use, you probably dont need super high bandwidth so i dont think that will be an issue. This also wont be used for remotely controlling robotics or drones, so latency going up 1-200ms is not the end of the world. The real important bit is that the troops can communicate and coordinate, get warnings in time, get satellite images, etc.

The coverage is as you say going to be the thing that will take time to scale up, but that can only be sped up so much.