What if anchors were actually attached to the ground, like a space elevator? e.g. what if they actually had an anchor powering them that could be destroyed by land units, rendering them inoperable (destroyed)? Or perhaps the anchor could actually deploy a land turret instead of firing on land from space. Basically, I want the anchor to look like it has some reason to be stationary, space elevators need to be stationary, space elevators have a land 'anchor', it only makes sense that the anchor have an actual anchor . And no, it really doesn't have much to do with balance, but I think it would be interesting.
It would be interesting, perhaps, if anchors could move, but they couldn't shoot while moving, and you could "deploy" them in places, at which point the would be able to shoot. When they "deploy" they shoot down an anchor to tether themselves to the spot on the ground. If the ground anchor is destroyed, they are no longer considered "deployed" and can no longer fire.