1) The only thing unique to the Priest/Priestess that I can find that has a bonus vs non-living creatures is the Staff of Asyra. Besides that, there are a few Holy spells that also have such a bonus, but any mage can use those including future Holy mages, it just happens that the Priest/Priestess is currently the best at utilizing them. Those few holy spells are Samandriel, Pillar of Light, and Blinding Flash. That is all.
Temple of Light? Pay 1 for 3 attack daze/stun ready marker action burst? It's like a Wizard's Tower with a very cheap Pillar of Light.
The problem with Necromancer is his match-ups, too many silver bullets out there.
3 Nature Mages will now pack Kralathor.
2 Holy Mages have Light attacks vs Non-Living.
Wizards/Forcemaster destroy his swarm with Obelisk/Orb and have greater mobility with Teleport/Force spells.
Warlock has Fire and Chains against Resilient (though Deathlock and total Poison Immunity hurts the Warlock).
Warlord has Sniper Watchtower behind a corner Wall (though Pestilence kills him, with Deathlock if Regrowth).
I'm not saying the Necromancer is weak (he has interesting synergies like "last action animate dead Malacoda"), just that he faces many silver bullets. To minimise these worries, you end up over-distilling the essence of his synergies. So you end up taking gambles that you won't meet a particular match-up. Just like my dislike of d12, I shy away from polarised builds which can sometimes give you walkovers and sometimes is walked over, it's just match-up lottery. It's why I avoid Jokhtari. She is amazing in some match-ups (now with Raptors, Thornlashers and Stanglevine) but Wounded Prey is useless against Necromancer and Earth Wizard (who now has 4 Oozes to add to 4 Golems for leveraging Necromancer's non-living synergies without his undead liability).
In fact, despite Corrode (which ended up peripheral), if you create a crosstab of mage vs. mage, Earth Wizard's 8x non-living level 3s build comes out possibly strongest against other mages. Last time, he stole Warlord's Earth spells. Now he steals Necromancer's Non-Living synergies. 4 Golems, 4 Oozes, 4 Wands, 4 Teleports, just add other tricks to suit taste. The only thing to compete with Brute's cost-benefit ratio are Golems and Oozes (which do not trigger Bloodthirsty).
So far the most interesting Zombie build I've devised is "Forcemaster Brute Squad", opening sprint to NC then 4 Zombie Brutes turns 2-5 and possibly 14 Channel by turn 5 (as per my post in Zuberi's Zombie Horde thread), using Forcemaster's unrivalled ability to manipulate board position (Force Pull, Stumble, Force Hold, Force Push, Force Wave) to allow your Brute Squad to solely focus on enemy mage only (moving a guard away or a mage from multiple guards) while Forcemaster utilises her own defences against any counter-aggro. As I am learning the subtleties of this awesome-looking Jedi/Sith Lord, I am excited to see if this works but the theory (Force spells complement Lumbering Brutes perfectly) feels sound. Although I'll probably slow down mana acceleration for the spell action advantage of a Forge.
Maybe the undead horde works. Just that a horde is by definition a "win more" over-commitment, waiting for an Obelisk to fall in a guarded distant corner. It just feels like "over-playing your hand". I hope I'm wrong because thematically, raising the dead is much more appealing than tending to my garden.
The Druid on the other hand seems so much fun (once you suspend disbelief). Bear Strength on Raptor Vines. Hawkeyed Thornlashers snatching through Bloodspine Walls into a safe Eagle Winged Vine Snapper and Togorah with Cobra Reflexes (shame no counter strike). I never thought I'd like vegetables so much. Shame she dies to fire (Renewing Rain doesn't solve Flame +2). It's a match-up lottery again.
Back to the thread: I think a certain flying skeletal undead dragon not making the cut may have been crucial to Necromancer's competitive viability. I truly hope I'm wrong.