Emmmm.....

:smile52:

Well, actually, demons are chaos – it's a race created by Urgash, the primordial dragon of chaos.

Necromancers worship Ashera, the dragon of creation and order, who is the opposite of her brother Urgash, and chaos is unacceptable to them. They are among the main demon hunters (let's remember the campaign of Arantir), which already shows their inclination towards the magic of creation (summoning). In addition, the spell "Raise Dead" belongs specifically to this school of magic. This race is dark, and light definitely cannot be associated with their guild. That is, based on the schools of magic of darkness and summoning, and based on the method of exclusion (considering light and chaos), we arrive at the necessity of giving them (necromancers) darkness and summoning, and not light and chaos.

Added 6 minutes later
By the way, in the original game, Necropolis and Inferno have exactly these schools of magic.