No reason they couldn't have friendly philosophical disagreements.
Druid: Without death, there is no chance for rebirth.
Necromancer: All your animals make use of corpses, so what is the difference if i do as well?
Druid: But you do so in an unnatrual way.
Necromancer: Magic is a part of the universe, using it is not unnatrual.
Druid: Death is also a part....
Monster: RARRR!!!
Necromancer: I'm afraid well have to continue our discussion another time. We have more intimidate issues.
Druid: Don't let death come to you today my dear necromancer, we have much yet to discuss.