In my opinion, destroying Castles diminishes the strategic depth of the game. In the standard version, the enemy's Hero and their Castle are almost equally valuable targets. When structures can be destroyed, the Castle becomes the primary target, as capturing it allows you to hand it over to the enemy and ultimately crush them after some time. On this map, I captured three flags simply by taking Castles, and afterward, when encountering their Hero, I either fled or surrendered with minimal losses. After encountering my Hero, the AI didn't return to reclaim its Castle, preferring to lose after 7 days. One of these "homeless" Heroes approached an empty Necropolis Castle under my flag on the 7th day but didn't attack, stood at the gate for a day, and then disappeared. As I've mentioned, the AI focuses more on defense than attack. There's also a peculiarity in the AI's behavior: it doesn't keep a large garrison within the Castle itself, making it easy to capture. Knowing these details turns the game into something very straightforward and easily predictable. The fact that mines are used more often doesn't affect the game's appeal, but the AI being in a vulnerable position certainly does.