Herdier is amazing! Once it learns Work Up and Take Down, it's very very useful. It's attack is high, it's defense is good. My Stoutland has Work Up, Take Down, Rock Smash, and Crunch. Crunch takes care of pesky psychics, Work Up Take Down combo is excellent if you are running into fainted pokemon that you can't bring out for a SE move. I gave it Rock Smash for the normal gym.
My current team is
Stoutland
Serperior
Victini (cheater I know)
Tirtouga
Zebstrika (Blitzle sucks but once he evolves he becomes pretty good, his def/sp. def still sucks, but his speed is outstanding)
Tranquill (just caught, leveling it, needed a flying)