Cleon
Legend
Maybe the reason the standard Netherese zombie has 6HD is just that they're usually made from people with levels?
The problem with that is the description it pretty clear that any old peasant can be turned into a Netherese Zombie with 6 HD, with "entire villages" being converted.
Hmm, how about we make the rank and file Netherese Zombies comparable to Vampire Spawn, with fixed HD and lower mental stats, by doing something like this:
If the subject has 5 or fewer class levels, they come back as a 6HD "base creature" Undead without class levels.
If the subject has 6+ class levels, they keep their class levels and become a "templated" Undead, which may be independent of the Lich Lord.
If we're keeping Int 10 (and presumably some cap on other mental stats), that would maybe be enough of a penalty but would gimp casters too much I think. Let's just ditch the 2/3 thing or come up with some creative SQ, like a restriction on actions (not as severe as a normal zombie, though).
Upon reflection, I think we could forget about the cap and just give them a penalty of -4 or so on all their mental stats. An ordinary joe character with the non-elite array has Int 13-14 tops, so that puts the smarter civilian Netherese zombies at Int 9-10.