I agree that it is difficult to effectively command your units with these limiting camera zoom levels. I also experience severely slow framerates the more I zoom in on ground battles.
On this note, I have another concern. I can rotate the camera left and right and up and down from a fixed position in space...on the ground I can only rotate the camera left and right and zoom up and down. In some of the screen shots and videos of gameplay it looks like they are getting camera angles that we aren't able to have in the demo version. Does anyone know if we will be able to pitch the camera up and down in ground battles once the final game is released? In other words, will we be able to look out onto the battle field form a horizontal angle that isn't from ground level. (like when you zoom in all the way)?