Do we know how the battle mechanics work on this? If the encampent defence and health is reduced to zero, does that mean a unit inside doesn't get any defensive bonus? And somehow ranged units can't seem to touch any unit inside an encampent even if the encampet itself has been bombarded to zero health. I may be wrong but I remember like it was the case when I last had such a battle. It seems you need a melee unit to attack into the encampent so in that respect it seems to act just like it was a stand-alone city as regards to battle mechanics.