Well, a castle is a castle, especially in Heroes 3.5, because the towers increase damage after winning sieges. Once, I held a city for 3 months (I started a map with 200% resources, S difficulty, 7 opponents, and I had a Conflux). It took 4 months to gather resources and build everything in the city. I was attacked 3 times a day, and I only won after 5 months. But by the end, the towers dealt 1300 damage! Imagine, the side towers dealt 1100, and the central one dealt 1300! That's when I realized how powerful they were! So, a Castle is Power!
In my opinion, the damage dealt by the towers in a castle depends on the Hero (the stronger and more powerful he is, the more damage they deal!). And this also determines whether you will control them or the computer will do it for you!!!

Как много в жизни есть путей
Для добродетелей и мира.
Я вернулся...