I just checked their unit lineup - they lose the Swamp Guard and Serpent Dancer, and replace the normal Sauromancer with the red Sauromancer (D3 F1 ?A1). They still keep all their normal priests, Sacred Serpent, poison slingers and the Empoisoner as well as their more mundane troops.
They also start with a free Tomb Priest in addition to their normal Commander, 10 City Guard, 15 Light Infantry.
It occurs to me that they are one of the few nations that might be practically able to Mass Protection a horde of undead...
(most likely shaman leading a communion of other shaman - although they get no capitol nature gem income). Combine with Royal Protection for banish resistance (as banish is armor negating). I'll have to try this and see how it works.