How to effectively use quick battles (autobattles)?

I tried, out of curiosity, to "tackle this cactus," but I couldn't! Charna seems to have a Sphere of Vulnerability (because when attacking golden dragons, death knights inflict a Curse), which gives her a significant advantage! But we can't resurrect the golden dragons.
Why I became curious: I abandoned that campaign on the 3rd scenario precisely because the necromancers develop too quickly (compared to me), and the Veil of Darkness helps them a lot. It requires a fast pace from the start, and the further you go, the more important it is not to fall behind in development, because the gap carries over to the next scenario, and eventually, you realize that you can't handle the enemies.
Because of this, I got discouraged and didn't even try to complete the other story campaigns, although they might have been within my capabilities. In general, I only completed "Long Live the Queen!" (which was quite easy), and my interest in campaigns waned.
Since then, I've definitely become a better player, but I still haven't felt the desire to complete the campaigns.