Ninetales - Flamethrower or Fire Blast instead of Heat Wave. But since you said the team was for doubles/triples, maybe use a Heatran somewhere in the team.
Hydreigon seems fine.
Infernape - Fine as it is.
Salamence - I suggest replacing it with something that can abuse Sun.
Leafeon - Aerial Ace instead of Quick Attack. Since it's choice banded, I don't suggest having Sunny Day on the set. Not good to be locked in on that if it ever happens. (which..for me, it has...)
Starmie - It's a water type in Sun, so I don't think it would be very useful. I understand because Natural Cure + Rapid Spin. You could use Donphan as a spinner and set up hazards.
hurr what do I know how to pogaymanz