Okay then, here's my rate.
Focus Sash Ninetales isn't a very good option, as Heatran leads are very common (I see them quite often, actually, mainly to scare off Ferrothorn. I even used a Heatran lead in my stall team.) and Ninetales can't do anything to them. I used a SubDisable set purely for troll reasons. However, this set seems good enough.
I actually got nothing for Scizor. Swords Dance Scizor has also worked fine for me. However, I used Life Orb over Leftovers for the extra power. As if Scizor is going to survive a fire type hit...
Leech Seed and Sleep Powder on the same set? I'd go for Growth/Sleep Powder/Earthquake/Giga Drain to allow Venusaur to set up and sweep. At this point, no one can stop it, save for Choice Scarf Latios, Mamoswine, and Weavile.
To take some weight off of Ninetales's chest, why not use Sunny Day over Substitute on Rotom Wash? You can annoy Politoed and Tyrannitar like this. Also, use Volt Switch over Discharge.
Sorry, but Jirachi is almost better in every way compared to Metagross. Better speed, movepool, and arguably ability helps it a lot. Doom Desire, while unreliable, can dissuade a Tyrannitar from switching in on Ninetales. It's wish-passing ability also helps a lot in a team that doesn't have much healing. It can even provide Stealth Rock for you. I would use a set with Stealth Rock/Iron Head/Elemental Punch/Healing Wish. Healing Wish is a great asset to the team. Can you imagine the opponent's face when they think they won the weather war and you having a 1HP, paralyzed Ninetales in the bench, only to see Jirachi using Healing Wish to completely restore Ninetales, HP, status, and all, and Ninetales doesn't even have to take entry hazard damage until it is fully healed!
You need Shell Smash Cloyster, period. Also, no Toxic Spikes, especially when your team utilizes the art of setting-up-and-bashing-opponents-till-they-faint. The residual damage won't do much for them. As you already have two set-up sweepers, why not a revenge killer. A Choice Scarf Starmie with Ice Beam/Thunderbolt/Psyshock/Rapid Spin could help out the team a lot.
Your main threats are Heatran and Swords Dance Scizor. I think a Zoroark can counter both, but not when Scizor is at +2. However, Zoroark's Focus Blast and Flamethrower can take both of them. Even better is that you can masquerade Zoroark as another one of your pokemon. Take Venusaur for example. The guy is taken down by Choice Scarf Latios. Send in Venusaur, the opponent switches in Latios, and bang, Latios is Sucker Punched to the afterlife. You could also disguise Zoroark as Ninetales when the sun is up. When Tyrannitar switches in, boom, Focus Blast to the face. I know you might not like Zoroark, but it might work out for you. It's hard to use, but it can play mind games on your opponents.
Hope this helps.