The wrecking balls are my backup anti-armor. They are there strictly because they can be forgotten about. Five trukks rolling around, chasing skimmers is okay, especially since the focus should be on those
MANz.
My main anti-armor are my
PKs. I couldn't think of anything more orky then that. I have 22
PKs on the board in as many as seven groups if I detach the warbosses.
As for elite armies, I think you are right. I would have a pickle of a time against Deathwing!

I am still a noob so I am not sure of which different kind of eite armies there are out there, so I am not sure how they would stack. I actually would feel semi-okay against some Zilla lists. The big chore would be to get multiple squads to the big monsters and engage two squads against one
TMC. I may lose some, but with that many
PKs, there goes whatever they were attacking.