I know this idea is pretty "sick" (pun police
) but what would you think about a dynamic population system & popularity? like, nomads coming in (through the front door, not just appearing) supplying you with people that are needed to create military units (sometimes nomads also come in with supplies or disease) if your popularity is high. But if your popularity is low, then people leave your city (out the front door, not just disappearing), leaving you with little people to support your growing military. And popularity is affected by things like hunger and disease. If people agree to this idea, i'll post a new thread.