Ash's Unova Team — Speculation and Hypotheses
Currently, Ash's "Staples" are: Pikachu, Oshawott, Tepig, Snivy, and Scraggy.
Now, his "Rotational Members" are: Tranquill, Swadloon, Palpitoad, Roggenrola, and possibly the oft-mentioned Krokorok that was set to appear in the Plasma-dan mini-arc...