If you're fighting on the outer shell of a spinner and you do enough damage to the terrain, wouldn't that put the inhabitants at risk?
It seems sensible that if damage is done to the spinner, a bunch of people in mechs with precision weapons that won't damage the spinner should turn up to arrest all combatants (or possibly as soon as the battle starts). Does the battle engine permit a battle with three sides at once, or can it only handle us vs. them?