I had a sequence where my Zombies started out as the basic template in the book except that the spine was the weak spot.
But...
The "ganglia" growing on the spine got BETTER in each new generation until the resulting Zombies were as smart as people and could use complex machinery and had overtaken a military base and then had military grade armaments and armor AND the training to use such in the most recent batch of Zombies...
Which was where the game stopped waiting for ATZ...
++++++++++++++++++
Skel: "Ever seen a drunk Lich before?"
Nort: "An drunken undead wizard? How's he get drunk?"
Skel: "It ain't friggin easy, le'me tellya.
Now pass me another beer or spend the rest of your life as a frog!"