True, that's a step further than me.
Those were going to be my duergar for evident reasons, and because as noted before, they are somewhat redundant. Then something about "orc" meaning corpse (could be wrong, though) came to mind.
Having hobgoblins, bugbears and goblins who look like less thin githyankis i thought i could change orcs, if i finally change my mind the name can be decieving and those deep orcs could be not actually related to the normal ones.