I’ve looked around on the forums and I have noticed that there is a few suggestions that may contain this but not in much detail. There are many that ask for the possibility for the player to remove their own buildings. However I am suggesting the possible addition of enemies being able to break into your buildings and through your walls. Whether it be through a titan just wading through your buildings, or a small band of goblins running up, laddering up the wall and into your base, or even a full siege with goblin/zombie armies outside your wall with catapults tossing rocks in ripping apart your buildings and tearing holes in your walls. Obviously this last one might be the from constant refusal to give tribute to goblins and constant destruction of their war camps.
Just a few thoughts! If it has been suggested before, I am sorry for mentioning it again.