Between the crazy launches and weight differences, Tiering is becoming pretty dicey, but it is still the best way we can inform people of what should work for them, especially as it takes into account tournament usage/success, and gives as a general idea of what to expect.
Keep in mind, also, that attack isn't the only thing requiring skill, Defense has a lot of extra depth. For example, any attack combo that doesn't hit the stadium and move straight away (it kinda "stalls" in place) can be easy prey for an aggressively launched MF-H Basalt Aquario BD145CS, with a decently manipulable CS, and plenty of people, including myself, have used that combo to defeat stamina in tourneys through aggressive launching.
Keep in mind, also, that attack isn't the only thing requiring skill, Defense has a lot of extra depth. For example, any attack combo that doesn't hit the stadium and move straight away (it kinda "stalls" in place) can be easy prey for an aggressively launched MF-H Basalt Aquario BD145CS, with a decently manipulable CS, and plenty of people, including myself, have used that combo to defeat stamina in tourneys through aggressive launching.