I'm not in this RP but I was wondering, the mechanics don't really mention what effect siege weapons have on actuals sieges on cities. I think it would be better to move the siege weapon effects to besieging a location. They wouldn't cause many casualties on an open battlefield unless the army was trapped in a enclosed location, like between two mountains. Just a suggestion.

Also you have to know that entering into this world, you have far less numbers than the humans, a horde won't work unless you have something you can dissolve the enemy defenses with, something that can cause them to fear you