My local VC don’t use Corpse Carts and Mortis Engines a lot so this is Theoryhammer. Corpses Carts and Mortis Engine means lots of things with Regeneration saves. Try a Lore of Fire Slann with the extra power die and lore mastery. Take a Skink priest to caddy a Cube of Darkness and also to help you aim magic missiles at places the Slann can’t get to. I’m also guessing they are light on ethereal troops (though Flaming Sword of Ruin will help you if you see those). If you find yourself with a lot of power dice in the first round or two you can try to zap the Mortis Engine early. (They explode when they die so you should try to get them to explode when your troops are far away). If you aren’t into high stakes gambling, throw your fire spells at the Corpse Carts to debuff the zombies. I’d recommend taking Temple Guard to get maximum utility out of the Cascading Fire Cloak (a Temple Guard makes Burning Head impractical but that’s probably the weakest Fire spell anyway). Save the Flame Cage for the Grave Guard and other large units of nasties. I’d back your Saurus blocks up with flanking blocks of Skroxigor, Kroxigor, Cold One Riders, and/or Stegadons (especially Stegadons). If you can fight the zombies 2:1 the CR will really stack in your favor. I wish I knew how to handle blender vampire lords. If you find out let me know.
Best way imo to deal with the blendr vamp lords is death magic - bane head combo. They only have 3 wounds. Also lore of light with bane head works too (if the vamp is running solo). Basically bane head and any sniper and or nasty single target spell should work'ish. Failing that, feed them skinks for 6 rounds