Necropolis vs. Stronghold

The problem is that Craig Hack has a huge amount of attack and defense, and the skeletons are easily defeated by his creatures. Also, how can you accumulate so many skeletons in a short time? The Citadel is based on the strength of the army (attack + defense). How do you fight him?

The power is all around us. Craig Hack has a huge amount of defense? Let's try to figure out where it comes from. After playing several dozen games as Craig Hack, you will be convinced that there is no mega-defense. So, it's the artifacts. And the one who plays more actively has more artifacts. Draw your own conclusions.
Now about the attack. Yes, it's a serious thing. But attack only determines when someone attacks, right? And who is going to attack? If you forget about building Capitols (just forbid yourself from building them in the next 20 games), and instead buy troops and crush everything around, the situation will change. And by the way, there are two types of Necromancer heroes. Choose the ones with 1-2-2-1 stats at the start. Galthran is better, by the way.