The Necromancer's Path.

Yes, that's exactly how it is. The script only checks the heroes available to the player within the map. A mod that unlocks Campaign heroes has already appeared in the map's history twice. But the first time was more amusing: the player simply added a bunch of undead to Markel's army and blamed me for it.

Added 1 minute ago

IchGViji, by the way, how are you doing? I remember you were trying to play through my maps.

Before I got sick, I was trying to play through "Price of Love," but Ter-Gelat was crushing me, and it was probably because I didn't get the spell and the bald hero, and the chance of getting a spell for the dwarf is very low, unfortunately, so a mistake in the first month has a high price, there's no mentor, and there's no time to mentor anyway in the first month).
But I had more success with "Path of the Necromancer," I managed to defeat Giovanni 4 times, Benedict 2 times, and the Orc 2 times.
Giovanni is constantly harassing Arantir, he keeps coming and coming, after 3 days, if the blue hero doesn't scare him, he comes back to my territory after each defeat.
This is all Arantir's karma for his invasion of Grimheim, which left that accursed Ter-Gelat there. What was the argument with Kirdan that started a whole invasion. Either Kirdan said something completely absurd, or Arantir was just not in the mood that day, which is why he started this mess.
I stopped at the point where Giovanni is getting stronger - I haven't had a chance to fight him yet.