Ok.
The next question is, when you still have Golduck, Poliwrath, Quilfish, Huntail, Gorebyss, Relicanth, Floatzel, Armaldo, Tsunbear, Omastar, Gamagerogue, and Seaking is rain offense really dead?
That's where I disagree with you. I feel like banning the sweepers will give the best of both worlds, as there are a shit-ton of lesser rain sweepers waiting in the wings. We can somewhat preserve the rose, while removing the thorns.
(In that metaphor, the rose is the metagame, and the thorns are broken elements.)
Ah, but what if Floatzel, Poliwrath, Qwilfish also prove to be broken as well? Ban them too? After all, no one would have seriously considered Ludicolo for Ubers before permanent weather. I live to see the day Floatzel will be called Uber, lol.