Blarajan's post is mine. Cottonee is a solid B teir mon with a notable niche and a few notable flaws. Aipom and Meowth both just lack that extra dimension that you want in your team. Sure they both are fairly powerful with a Life Orb and respectable 70 attack (or tech boosts) but they're both paper thin, and really cant do anything besides hit switch ins with uturns before you start losing momentum. LC is a teir where there are a couple of elite mons and thats because they're multi-faceted in one way or another. You'll notice that very few things in the A+ teirs have only one role in the game. Meowth and Aipom lack that dimension, as i said earlier but they're also sub par at the only thing they can do - beat out by the Mienfoo specifically.