An interesting opening, Zuberi. A lot of long-term planning for a mid range strategy The Shaggoth Growth play (full action, 1 point and 3 mana for +1 malee, +3 Resilient Life) needs to stay with a source of Crawlers (slowing your threat tempo) and will soon get scary! But if you over-commit to any huge threat, a wand with Force Push could keep him out of Frenzy range. As you can't Sleep him, maybe Banish will make an appearance if he becomes popular. I do like sacrifice mechanics so I hope this works great.
But are you obsessing too much about using the Ring and Amulet? I was thinking something a bit more direct, "in your face", like...
C10: (20) Crystal (15) start corner, double move NC
C11: (26) Brute (15), Crystal (10) back edge
C12: (22) Brute (11), Crystal (6) next to start corner
C13: (19) Brute [8], Crystal (3) next to other corner
C14: (17) Brute (6), Teleport/Force Wave/Tanglevine
(I kept them all as Crystals rather than a Death Ring to keep it transferable with Warlock)
This is against the dream of no-disruption (which never happens). In reality, you should never get to Channel 14 by turn 5 and you will have to cast Tanglevine or Force Push or Stumble (so apt) to pressure the opponent early. Once you have enemy mage wounded with 4 Brutes, time to cast the Frenzies. Just focus on the mage. Evade may be useful to avoid wounding guards who will then be distractions.
It goes without saying that against a Druid, turn 2's first summon will be Lord of Fire and a relevant enchantment dependent on situation. In fact, with Krathalor available, this may be the play against any Nature mage.
That’s the problem: it’s only his 10 Channeling that’s stops me instantly switching to Warlock. Plague Zombie looks an interesting Eternal Servant as you need to leverage his abilities. Idol of Pestilence is two-edged as it will distract Zombies from threatening the enemy mage so you are committed to a slow swarm "eradicate all enemies" attrition strategy if you go that way. Obvious Poison defences (Malacoda, Gas Cloud) also create these wounded minion distractions and are useless in mirror matches. Everything commits to swarm attrition.
I think more interesting could be a Skeleton Soldier Fort build with a Wall of Bones partition, Archers on Watchtowers, Knights guarding against Flyers and Mort healing (Wraiths making sorties through the wall, also not undead vs. Kralathor). I also expect openings like...
C10: (20) Moonglow (14), Acolyte (9)
C11: (20) Altar of Skulls (11), Acolyte (6)
C11: (17) Wall of Bones x2 (5), Acolyte (0)
This triggers Altar turn 5 with Mort appearing that same turn. Reassemble (and Acolytes while they live) should prevent a breach. As vine range requires line of sight, I think Wall of Bones may prove to be a key card (additionally useful at penning up your Zombies' mage prey).
The main issue with Zombie swarm (as opposed to Brute assassination) is Bloodthirsty is poor against Nonliving (e.g. my Earth Wizard with 4 Golems and 4 Oozes), especially the mirror match which will be common to begin with. Skeletons don’t suffer that bad match-up. Still, those Brutes are sooo sexy...
I have the Warlord problem when building for the Necromancer. His army seems too ambitious, slow and long-term. Now the Druid is a control player’s dream, I’m even considering Thornlashers in Fire Wizard with Hydras (wounded are great distraction for weak Zombies like Crawlers). I love the Necromancer mage sub-class (harking back to my D&D Necromancer who searched musty tomes for ways to bring his dead love back to life) but the Druid's clever mechanics, unrealistic combos and under-costed creatures (9 cost level 3 vampire with regen?) feels so much more stronger. I really hope I’m wrong about the Necromancer but secretly I suspect it’s Warlock for the win.