I think that many here would agree that the series in single player has way to many sieges and so they might become somewhat repetitive.
So I thought why not add a mechanic that when a large army surrounds a settlement that has these factors:
1. No general.
2. Disloyal general
3. Small/weak garrison
4. Is very unhappy
5. Is small/peripheral to the empire
6. Has been long under siege (but not long enough for to run out of food)
7. The faction is on the losing momentum
8. The besieging general has certain traits
9. Faction leader has low authority
10. The besieging faction is same cultural group/being in a civil war
Then the settlement would have each turn, or even during the first siege a certain percentage (depending on how strong are the factors) that it would surrender without even asking the defender (Player/AI) or by giving the attacker a choice like "we will surrender if you do not sack the city".
I think this would be historically accurate and would force the player/AI not to sit and wait for the enemy but to fight in the open like it was historically.
So what do you think?