Obliterators, especially enough of them to actually matter, are expensive as all hell, and so is the rest of their anti-tank. This codex was not designed for the world of everyone's in tanks and has a bunch of anti-tank weapons and does really poorly in said world. There's a reason I quit playing them and if you think that I intend to go to a bunch of tournaments and rack up wins with my chaos, you are sadly mistaken. I have other armies that do that.