As long as the enemy army is besieging a settlement the said settlement will always aid in the battle. The only thing you can do is attempt to rush the enemy army with your main force and hope you reach them before they reach your reinforcements. Also by repostitioning your main army to attack from as close to you settlement as possible your reinforcements may spawn closer to your side of the battlefield. Also you can try controlling reinforcements to move them out of the way but you will need to attack with your main army as well when you have artillery in your reinforcing army. I think that all makes sense.
Bookmarks