"Frida's Dilemma" - "Negotiations" [Campaign 1, Mission 4]

What's the point of capturing it?

Capturing a castle is not a condition for victory – that's correct. The developers specifically shielded the player from this "randomness" by placing a strong garrison. But, since there are no more interesting battles left for you in the campaign, I suggested it as an option. The possibility of capturing a city is nothing more than a check to see if you've done everything correctly: leveled up your hero, chosen, and used magic in battle. "Dark" magic might help, but there are also dragons in the garrison, and there are many of them, so don't forget about them. They are what make the battle for the garrison difficult. Without them, this battle would be at the level of a "warrior." And regarding the topic of "template-ness" – capturing a castle is not described even once, whereas the walkthrough of the campaign is broken down into every detail. There is room for creativity here.