What skills should Necromancers take when facing Orcs on a very large map?

The Darkness Shroud is useless; it won't save him from Berserk/Subdue. A Necromancer without magic is a Necromancer who has already lost, so magic is a must. Besides, if an Orc spends as many as 2 skill slots on Darkness Shroud, that's even worse for him. For the late game, Lucretia is the best choice.