For the Butterfly Dance sweeper set, I think the moves should be FlyDance / Bug Buzz / Sleep Powder / HP Fighting. With HP Fighting, Heatran and Lucario each get hit 2x supereffectively, and you get a neutral hit on Skarmory at least. Fighting might not be individually as good as Ground, but you gotta be able to hit Skarm. Plus, Bug/Fighting combined with Tinted Lens pretty much gets neutral coverage on almost anything, doesn't it?