They're not zombies so much as ghouls really, they don't hunger for flesh or anything like that. They are corpses summoned back by magic to do the bidding of their magical masters, which I am pretty sure puts them down as ghouls. Even in the books they are described as ghouls.
Actually, Ghouls are the ones that eat corpses. That's their defining characteristic. The one of Zombies is the slow, shuffling gait.