So I was just informed that Necron HQ can only take 1 artifact. If thats the case why not just use a Destroyer Lord over an Overlord?

Its more mobile, its tougher, the preferred enemy everything kinda makes up for the 1 less in WS, it can take pretty much the same things as the Necron Overlord.

So a Mind shackle, Phase Shifter, Phlactery, Nightmare Shroud, Res Orb seems to be better than an Overlord with the same setup.