Driven not by skill, but by a desire to feast on flesh, Zombies are good, terrifying fodder in melee.
Zombies are shambling horrors that stagger towards the enemy battle lines in a noisome horde. Grotesquely reanimated corpses, they are compelled by the Dark Magic of a Vampire or Necromancer, and driven by the will of their master to commit acts of extreme violence. To call the way a Zombie attacks "fighting", is perhaps to give the foul creature credit beyond its due. These sickening half-things have no skill to speak of, but are instead driven only by the insatiable urge to rend, kill and consume the living. Any warrior unfortunate enough to be pulled down by a Zombie horde will find himself torn slowly apart by a mass of desperate clawing fingers, his flesh gouged from his body in grisly, glistening chunks. The fortunate die quickly, but those unlucky souls who are trampled beneath the horde spend their death throes in miserable agony as their innards become a crimson feast.
The dead do not rest easily in the Old World. Those summoned by Vampires and Necromancers no longer have mortal concerns - they serve only their master's will.
The Dark Magic binding has failed. Both flesh and necromantic energy slough off the subjects, leaving naught but dust.