Does it bother you that already on the first turn of the game you get a message that faction has been destroyed? Do you also feel that the unbearable ease of destroying a faction in the campaign makes the campaign too short?
My proposal is very simple - to increase the garrison that the settlements will get. Every settlement will get a big and strong garrison, regardless of whether it has special buildings, etc.
Capital cities of course will get a particularly large and powerful garrison.
(By the way, speaking of capitals, in old TW Games it was possible to change the capital city. Why does it no longer exist? Sometimes you have a lot of port cities, and you still cannot trade with anyone because your capital city is isolated).
Even in battles I would like the units to have more armour and health and less of mele attack. Because sometimes you send a unit to fight with the enemy, and by the time you send another unit to take them in the back - the first unit has already been eliminated. The latest proposal will allow for more use of tactics on the battlefield and out of discretion, not pressure.