Forgive me, I am a big dwarf person when it comes to Phantasy games such as this..
- If you added Dwarves to the game, their defense capabilities would be that of mainly runes that would have an effect against enemies in front of their great walls, as they arn't too big on magic, runes are a great side-way to it.
- I also think they would have oil pots, because those are always useful to make the orcs burn that think they can scamper up the walls.
- They wouldn't have trebuchets due to those machines being too big, however catapults would work wonders on enemy invaders.
- Dug-out Spike Traps would also be a useful deterent, however Dwarves like the thrill of fighting enemies such as pointy-ears or orcs at close range.
So they wouldn't have that many defenses, just mainly the runes I spoke of above.