Yeah, I think Ninetales is fine where it is in A tier. While it obviously does provide instant Sun from just switching in, you also have to weigh in the fact that Ninetales still uses up a teamslot. I really think Ninetales is the worst Pokemon in OU right now. Offensive sets are outclassed by Heatran and other Special attackers in the tier, while defensive sets have trouble holding their own against other weather inducers. It really doesn't pose any threat at all, apart from being able to take random Scalds and such. People are pretty much forced to run bulky Ninetales to make it stay around for longer because the benefits of Sun are much greater than that of any other weather. The different between Ninetales and other weather abusers are that the other weather abusers actually have some use. Hippowdon can be used as a wall on both sides of the spectrum to take hits, while setting up Stealth Rock, being able to phase out stat boosters and is the only weather inducer with access to reliable recovery. Tyranitar is a formidable special wall under Sand and is often used to trap Lati@s and other special attackers. Tyranitar can also perform an offensive role with a Choice Item to take advantage of it's great attack stat. Politoed on the other hand can do both roles, Choice Sets can act as great revenge killers to opposing weather abusers, completely twisting the momentum upon switching in, while Politoed can also viably run a defensive set to wall a lot of attackers on either defense. Ninetales doesn't really fit in here, as there's nothing it does particularly well. It's Stealth Rock weak, has a pretty bad defensive typing and a bad matchup against 3/4 of the other weather inducers, which are the most likely matchups for Ninetales.
This is why I'd also like to propose that Venusaur be moved up to A Rank. There's no doubt it is the most potent of all chlorophyll abusers, and the only thing stopping it from sweeping teams is that 4mss. Venusaur is pretty much the sole reason that weatherless has trouble against Sun, because when Sun is up, Venusaur isn't going to be outsped any time soon while it can also boost it's offensive stats easily. I also find playing against Venusaur is similar to playing against Genesect, in the sense that you really need to scout for all of it's coverage moves. The coverages moves of choice are what set Venusaur aside from other weather abusers, as Venusaur can run viable coverage moves to break through it's checks/counters, while under Sun Growth Venusaur can break through Eviolite Chansey, arguably the best special wall in the game.
Nominating Venusaur for A Rank