Fallen Shaman are Demons. There are five types: Fallen Shaman, Carver Shaman, Devilkin Shaman, Dark Shaman, Warped Shaman.
Fallen Shamans will raise dead Fallen, but only of their own kind. Carver Shaman will not resurrect dead Devilkin foot soldiers, for instance. Regularly shaman can not resurrect each other; just foot soldiers. Boss Shaman can resurrect other shaman, but only of their own type. Post v1.09, shaman bosses no longer spawn with a pack of other shaman, just with foot soldiers.