First off there's this bit:
"Most undead, even those that seem intelligent, are this sort of creature - driven to inhuman behaviour by lack of governance of a soul and a hunger for life that can't be sated. Nearly mindless undead have been infused with just enough impetus to give the remains mobility but little else."
From which I take it that they have some degree of "mind". Add to that that, in order to follow commands, discriminate intruders from rats or masters or fellow guardians (or whatever) and in order to fight with any facility at all, they must have some degree of basic understanding and instinct. Add, also, that they have the "hunger" referred to, and I see plenty for an arcane "lampoon" to work with.