They are basically Rhodoks. Pikes and crossbows to combat knights and men-at-arms on horseback. The horses they’ve bred to their size simply don’t compare to humans’ so they only use them for domestic affairs.
I don’t really care about being original with my work, I just do what makes sense.
They migrated from the netherworld to discover a feudal world already claimed by humanity, so they started hanging around in mountains (somewhat spreading into thick forests later,) as that was the only thing that could guard them from their one tactical weakness: cavalry.
Eventually the lords relented and gave them the land they squatted in to them.
Their women are simply a weaker, shorter, more lithe and less hairy, egg-making version of themselves, as with the horse-lords, (humans.)
They are intelligent but have a sort-of-autistic reaction to social pressure where they find it difficult to convey their thoughts with words and if pushed may become rash and convey their thoughts with angry words and violence. Which does no favors for their reputation as stupid land-grabbing barbarians.
In human society, they make for mercenaries, hired-hands and traders.
In their land, they maintain strong ties with one another, herding goats and farming wherever possible on the slope of a mountain all stair-step style.
They treat their arms in a way that turns the metal dark blue and invented stone cooking ware.