As long as you avoid a couple of things. First, just because something is theoretically capable of killing something doesn't mean it's actually good at killing whatever it is. Second, don't list tailor. There's a difference between "I'm going to try and fit in a few more lascannons so I can face the WK" and "I'll take X, Y, and Z units that no one ever takes under normal circumstances because they happen to be really good against the WK and the WK only". And third, realize that you're not facing the WK in a vacuum. DE Venom spam kills Wraithknight pretty easily, but Mechdar hard-counters DE Venom spam, so that's not necessarily a good route to take if you're facing Eldar.