About the lower tiers, you could possibly help out and teach how to use someone's favourites in lower tiers as NU is so large (there were 206 in there at the end of Gen 5), and almost anything has a chance of doing alright in there. Heck, stuff like Skuntank, Samurott, Haunter, Alomomola, Articuno, Audino, Cacturne and even Golbat did nicely last gen. Most battlers do know that using favourites isn't a good idea, but you could base a team on a favourite and get the right support for it.
Ignoring that, we'd need a good amount of battlers to actually make this work well.