I think Sword of Judgement is a very real artefact on the Scar-Vet on Carno. I dont think you should ever go for stuff like Doppelganger because he's simply not killy enough. Most big bads got really good save with rerolls or Ethereal amulet (almost all Maw Krushas use this), so you really need the MW output tbh. The fact you can also give him multiple +hit really makes Sword of Judgement shine. I would probably rather have him hang back behind his Saurus buddies, give him fly and charge when you want to, so you can pick the fights on your own terms.
Not going to lie, the 2+ unrendable on maw krushas is pretty ridiculous, but atleast only 1 maw krusha can do that. Good thing sword of judgement is so good on scar veterans with warspears. Wish I could go out and test this theory...
He might have thought that he could do it, since the Vampire Lord on Zombie Dragon can increase his save and get Ethereal Amulet. The rules are different though - The VLoZD says that his characteristic is a 3+ with a shield (not +1 to save), where as the Maw Krusha gets +1 to his save. One is a modifier, the other changes the warscroll value.
Me:I didn’t murder him, he died of natural causes the police officer: you pushed him off a five story building me: gravity is a natural thing