You could use the Jotun Vaetti sprites, or the goblin sprites from Conquest of Elysiun. Both have small inhuman spearmen and wolfriders. CoE also has an orc faction, which has orcs armed with large, two-handed swords, and spears/shields, and Orc Chariots, and several commander sprites that could be elite units as well. They're far from Dom-quality, but I think they'd be a very good starting point - apart from the orcs being 20 pixels high, instead of either 16 or 32 which would make them the same size as Dom-humans.
A screenshot of a collection of CoE orc units is attached. It's a bmp file.
