Since RTW I wanted to use my artillery to burn down a city destroying all their infrastructure and then retread. But I have never done it because it will give to my general bad traits.

I think that all these tactics are usefully in real live but in game most off us play to conquer new provinces not to weaken the enemy. So if they were implemented I am not sure if people would use them.

Anyway it should be better let the player decide which kind of war prefers