I only have 1000 points of Dorfs so it's kinda hard to make a big army. We also loads his list with mortal wound shooting like Lighting cannons and the warpthrowers as I said. Also he runs the Chaos alliance rule that gives his units plus one to hit against order along with the random +1 to hit that Chaos gets. He ends up having 40 clan rats hitting on 3+. He usually reaches objectives first thanks to the +1 movement bonus because of the screaming bell and just tarpits my units trying to get there and flanks them with the warpthrowers. I've won before, but It is usually through lucky dice rolls and with like 2 models left.