New creature abilities.

Regarding the ability to break down walls from a distance, it creates an imbalance for the city – it lacks passive defenses like ranged towers and a moat, and as a result, the purpose of building a city is lost. Walls provide a bonus, but without them, everything can be destroyed remotely, without any special tactics.

There are several ways to negate even the castle's towers. First-level magic – Finger of Order. Older magic – Teleport. Creature and artifact abilities – Wave of Fear. I don't think there's anything particularly radical about destroying walls with catapults. This skill could also be given to Stone Golems and Gargantuars.