To lose - Witch Elves.
I loved seeing those evil bitches get run over by the Skullcrushers
Please, tell us how you really feel!


So what's worse, Witch Elves, Ahsoka Tano, Wesley Crusher or Vampire Counts?
I feel Warriors of Chaos are still more OP than Dark Elves as a whole, because with Dark Elves you can at least shoot them to pieces before they have a chance to get into melee (which is much more difficult with WoC)
I guess it depends on the army. The case of the Warriors of Chaos, it is very difficult to prevent the Dark Elves from hitting their lines. However, the Wood Elves probably feel differently and much more in line with what you suggest.
From what I have read, the "general consensus" (and I use that term loosely) is that the WoC and Dark Elves are roughly on par, and are both perhaps the smallest of fractions weaker than the High Elves, who are generally or most consistently voted as the strongest. Obviously styles make fights, so it will vary depending on the opposing army, army composition and the general's play-style/experience/etc.
but in this tourney the Chaos Warriors are of a subpar build,
Well the build that was suggested as the best, is the build that I used. I wanted this to be a community effort, rather than just 16 of my personal picks. I think that approach has worked out very well, and we've been rewarded with some interesting and unexpected results (a prime example of this are the Black Guard, but there are many others).
Back to the question at hand, there are generally three main Chaos Warrior builds:
- MoN - Halberds
- MoT - Hand Weapon + Shield
- MoK - Additional Hand Weapon
All three are widely used and accepted. Different generals have different preferences. Only the Slaanesh build is typically considered to be sub-optimal. I prefer either the MoN or the MoT builds myself, and go back and forth between the two, but others may feel differently.
That said, I do not think the Chaos Warriors are as overpowered as you believe them to be. They may seem like the very best, but once the price point is factored in, they are matched or even beaten by others (but still remain very very good). Of course, we'll have to wait until the end of the tourney for a bit more data to either support or refute my theory.
and the Hell Pit Abomination which was interesting to see (with the latter being available to me as a Skaven player)
The HPA is damn good and really holding its own against some very stiff competition. Come to think of it, for a guy who complains about the Warriors of Chaos being OP, you do own arguably 2 of the 4 strongest armies in the game (High Elves and Skaven).
Your roster of armies of, High Elves, Skaven, Dwarfs and Orcs & Goblins, are stronger than my ensemble of Warriors of Chaos, Chaos Dwarfs and Tomb Kings.

Maybe I'll have to trade in my Lizardmen for some Dark Elves to help even the score

(and no, I'd never trade away my Tomb Kings, even though they are by far the weakest of the armies I own).
They by all accounts should have lost so many times over, yet a few silly special rules have saved their arses many times over.
But those silly rules are what makes Witch Elves. That is literally what you are paying for. All units are reliant on their stat line and/or special rules. I don't feel one is any more valid than the others.