We are talking about the following single-player scenarios and Campaigns:
I tried running it. The first mission worked fine, and the hero's specialization in battle also works (upon the death of an enemy, it applies a weakening effect).
I ran it with the hero and was quite demoralized. The guards at the starting passage are more balanced than they seem. The Abyss Lords, of which there is 1, are Tier 6 level 2 creatures, and the Abyss Spawn, of which there are 2 at the passage, are Tier 6 level 3 creatures; they are stronger in terms of parameters. And we have a level 1 hero with a small army. By some miracle, thanks to the battlefield generation, I was able to win with the hero's attacks.

Next, there is a location with a couple of devils, but I was quickly asked to leave it; there is not much to gather an army from. After fleeing the location that threatens defeat for being in it, I ended up in a purely green world with huge squads of troops. It is unclear what to do. I ran it with the hero; I will need to try another difficulty level; maybe something will change.


Fans of challenges will appreciate the starting conditions for the hero