However there are several improvements I hope they will make. Please feel free to add to/dispute the list.
More dynamic
I.e cities can be retaken and refought over, or there are uprisings to put down in a certain area.
More responsibilities for the player
Allow the player to input more as they advance, I.e how to attack a city and what will happen to the (jarl-type person)*
And have these decisions actually cause something, like a poor tactic choice would lead to less men available or more objectives required to attack a city, or even fail to take over.
More ways of taking over
Not just the classic "take over the fort/city" but maybe,
kill off + replace a lot of nobles
Regicide
Spark civilian uprises
*Outcome of taking over cities
As previously said the player after a while should be able to decide what happens to the jarl-equivalent of each city taken over
I.e
Keep as jarl, this keeps the neutral and pro-opposition side civilians happy(-ish)
Exile the jarl, annoys the neutral and pro-opposition a bit but keeps your side happy
Execute, enrages the pro-opposition, alienates the neutral, but pleases the more fanatical civilians on your side