Two sisters.

the strength of the dwarf army, I believe, should be measured not by dragons, but by level 6 creatures. On this map, it is best to fight either defensively within the city or by attacking a city where the AI's stack movement is also restricted by the walls. Dragons have average initiative and can be easily trapped by a wall of swords and crystals (and upgrading summoning magic is not necessary) and then shot down by archers and hero attacks. However, warlords and earls in large numbers are a very formidable and mobile force with their very inconvenient first ranged attack.