1) Dwarf buildings are just cheat-level cheap.
2) The start for Dwarves is decent (shooters are already available at level 2, infantry almost never dies on its own, and the supply wagon compensates for the low ammo count of the shooters)
3) When playing on large maps, Dwarves have a clear advantage over everyone (except Necropolis)
4) Even 40% of those killed twice in a row toward the end of a game on a large map is not small at all.
I agree regarding the rush; that's the only way to get through to them. Only usually a proper rush doesn't work out, so you have to just hunker down (or gradually increase the skeleton population via reincarnation with a magical kick in the pants=))
P.S. Dungeon rules, especially Sinitar, but it's very difficult to manage the troops; only the hydras are hardy, the rest die like flies (it's almost a pity), and Deleb is what turns demons into a combat-ready army.