You definitely want a higher tier of guardian - jack up some skeletons, or grab wights. Or spectres that sidle out from the suspiciously-arrayed-dead-bodies-which-are-totally-not-going-to-get-up-and-murder-you.

Really, it's about the character of the place. If it's supposed to be a sacred or honorable space, you wouldn't put orcs inside. You might have some orc-ghouls chained up outside to ward off interlopers, but not inside the Tomb. If the dwarf was notably cruel and callous, a horde of Orc zombies or skeletons, preferably with a couple of "boss" mooks would be good.

My inclination would be to have the Dwarflord himself be a monster-maker (Wight, shadow, wraith), and the guardians are past interlopers who have become part of his guardian army. Exactly what kind may depend on system. 3.5 Wights make more wights, 5e Wights make zombies.