Ooo ooo - doubles is my sh*t - I got ya,
Alright so right off the bat, T-tar and Sand RUsh Excadrill is effective - but what items you got on both? Because that earthquake can really mess Tyranitar up, especially if there's a choice band on that mole. Also, Hawlucha is a very potent threat to both of those should it switch in, as well as both your guys being weak to earthquake in return. Assuming you're running Rock Slide on Excadrill, you're at least covered from obnoxious MChar Y's, but putting something with levitate or a flying type back in your team somewhere may be a good idea for switching out one of your leads. Especially since intimidate using pokemon will be unpleasant for both of them. As far as a defensive or bulkier pokemon to back those up goes, you may want something with a little utility assuming that mew is just for turning into another Mewtwo X, and no fighting water ground or ghost weakness - since you've already got 2 of each of those. Perhaaaaaaps, a Skarmory? That could be good. Any of Tailwind, Stealth Rocks, Spikes, Whirlwind, or the like would provide great backup for your other mons. If you want a more aggressive support, why not a prankster? Whimsicott has some nasty status moves, leech seed, also tailwind, and healing with giga drain / leech seed. Gliscor, has some nice physical bulk, can switch in on earthquakes with no fear, provide support and hit back, only problem is it does carry that third water weakness for your team. Mandibuzz can also switch in on earthquakes with no fear, can have defog to get rid of entry hazards, it's another that can have tailwind - brave bird, knock off, or foul play for keeping it out of being taunt bat, and plenty of bulk and other options.
