Which faction poses the greatest challenge for the Dwarves?

Well, if you consider yourself a strong and experienced player, then Tournaments are regularly held on heroesworld (and there is also a league). Why not prove your skills in practice, not just in words:confused:

I've been playing Heroes for about a year and a half. I think I still have a lot to learn. But such basic things as the confrontation between Orc and Dwarf in the late game are clear. If the Dwarf doesn't have Dark magic, then the Orc can really do something. And when a tournament is held, I will definitely participate in it, don't even doubt it.

Added 2 minutes later

Here's what I don't understand - let's say the Dwarf has advanced Light magic and "Righteous Fury" (switching to Light magic in a long game is predictable and justified) - and what is there for the Orc to be happy about?

I think the Orc's sacred word won't scare him much. But divine retribution will. Therefore, the Orc needs as much magic resistance as possible.