I don't think Hogs are over-powered. Firstly, they are expensive to train! I regularly use hog armies to trophy push, but very quick run out of Dark Elixir.
Secondly, they're a very testing troop to use. Use too many and you'll win with ease but feel like you've over committed but don't use enough and you'll find they get overwhelmed quickly.
Traps and archer queens are their worst enemy, I've seen my hog are stopped clean in their tracks by well placed traps!
