Yeah, the Necro matchup is not good. The Ichthalids are useless and I lose a battle of attrition without them. I suspect I could hide this weakness by adjusting the rest of the book, but I don't really know what I'd want to do. Zombie Frenzy isn't a great Graveyard strategy, and Skeletons lose to Zombies.
Creatureless Wizard is another bad one, though I'm seeing a lot less of that after the recent changes to Tower.
Brute Spam might be the best plan B, so far.