1) Death Magic (Heretic): Undead, Skaven, Dark Elves, Chaos (Can the Heretic religion be made playbale?)

2) High or Old Magic (Orthodox): Dwarf, wood elves, high elves, lizardmen

3) Light or Bright Magic (Catholicism) The Empire, Kislev, Brettonia, Tilea, Estalia

4) Waaagh (Islam): Orcs and Goblins (Islam will allow the Orcs to perform "Waaaghh" Jihads on other races)

5) Paganism: Tomb King (What do these guys name their magic?)
An alternative could be:

1) Chaotic: Norse, Kurgan, Beastmen, Skaven, Chaos Dwarfs, Druchii(alot of people will get angry, but unless we want to play on the conflict between the cult of Khaine and the cult of pleasure it should be ok).
2) Old Gods: same as in the post above mentioned above
3) Humanoid: same as mentioned in the post above
4) Savage: the "barbarian races", Ogres, Orcs and others who might fit
5) Forgotten Gods: including the Vampire Counts and the Tomb Kings