What kind of Ninetails is it? Drought may be an issue if you went that route. Ex: You use Greninja as a lead, it goes down, Ninetails comes in against something, the day turns sunny, Ninetails goes down, now you have drought still going with nothing that can capitalize on it, but what if I send out a fire type?
The point I'm making is that Drought is great if lots of Pokemon can capitalize on it in some way, but nothing on your team can except Ninetails. If you didn't go that route, then I see no issue.
unfortunately it is a drought ninetales. i'm going to ev train it to be a bit defensive, so it can take hits and so on.
but on the other hand, it can counter other weather effects, like sandstorms and hail.