and the Lord of Skulls is almost always going to have Invisibility and/or Shrouding from Be'lakor (who always goes with it) or the Grimoire for a 3++
Oh, I'm sorry, the Lord of Skulls has gone from 3x the cost of a Wraithknight to 4x, if you include Be'lakor. That's clearly why a Lord of Skulls with no invisibility on it (or with Invisibility failed, or with Invisibility denied) should still get shattered by a Wraithknight before it gets to strike.
Bring three Wraithknights for 900pts and I'll bring Aetaos'rau'keres for 999pts
So what are the other 3000 points in the list going to be, given that a Daemon Lord still can't be more than 25% of your list?
I concede that there are definitely some great Lords of War out there. I practically never see any of those Lords of War, however, and I know a shitload of players with (multiple) Wraithknights, though. And if the leaked super-detachment is a thing, you can take as many Wraithknights as you like after paying a few-unit tax, in a 1-12 choice. Like the 1-8 Lord of Skulls in a Blood Host. I think we can realistically expect to see and face 3-Wraithknight armies; I have yet to face a Stompa or a Cerastus Knight. I am fortunate in that regard, I know, but it doesn't make the Wraithknight any less incredibly powerful for it's dirt cheap price tag (as far as LoW go). It is one of the highest (if not the
highest, tied with the far more expensive Knight-Lancer) Initiative D-strength melee weapons in the game with a solid number of attacks, at this point.