[@Mardox]

To answer both your questions, yes. Though in the case of the ghostly solders, only War-Mages can summon them; Your War-Mages have to pick if they want to create ghost (Professional Units) or Corpse (Conscription) solders. They honestly just march with the army and act like any other unit you have, so if you order them to be the vanguard, they are the vanguard.