Two sisters.

I completed it in four months playing on "Hero" difficulty. I played defensively, staying in the Dwarf castles, and destroying the ballista in front before it could create openings in the walls (thankfully, the Dwarves have strong cities). After that, I focused on archers and flying units. The AI, with its superior army, would often retreat. What I liked was that there were challenging battles. In quick battles, the AI often retreats without inflicting any losses (I suspect this is a bug from the developers, so I had to replay without auto-battle for fun). The AI in the Dungeon's central city is passive and allows you to pass by. Thank you for the map. I'm waiting for more challenging ones.