You'll end up with strong and quite competitive troops. Gunnar. Mana doubler. Artifact market. That's already quite strong ;)

Forgot about the summoning portal. This is the main advantage of Dungeon when starting, not with Shafts. It's enough to defend a good nest, like cats or minotaurs, to get a powerful stack for raiding serious banks by the 2nd week. For example, a minotaur nest with them in the castle gives you 22 minotaurs by the 2nd week, which, even without the Shafts' troglodytes, can break through defenses quite well. But the dependence on the map layout is significant, yes.