You seem to be weak to Wash, Keldeo, DubDance ThundyT, SubCM Jirachi, and most sun teams. Some of your sets can also do with some clean up.
Firstly, Politoed does not want to be locked into Psychic. Psychic is only viable on the Bluff Politoed so it can hit Toxicroak or Keldeo. I would follow Remedy's lead here and go for Ice Beam
instead, as the water + ice coverage is invaluable. Finally, a small investment of 24 Spe
evs should outpace Wobby and Skarm, as well as min-invested Heatran and Scizor.
Secondly, I think you should drop Expert Belt for Choice Scarf
on Thundurus-T. It's amazing coverage and power makes it a much more useful scarfer than Latios (and tbh the scarf set is much more surprising than the EB set so you'll be netting more surprise KOs with its speed tier), who is too weak to really abuse Draco Meteor (or any other move). I'd sack Latios for bulky LO Latias
. Latias is an easy check to Thundurus-T who set up +2 (in either stat, so long as its not +2 satk AND +2 spe, as it can Draco OHKO). Latias also solves Rotom-W, easily tanking most of its hits, it can also wall Keldeo to death (and providing something for sun).
Give Scizor 248 Hp evs
instead of 252, so it can switch into SR a bit more, and then put the other 4 evs into speed to hit 8. Donphan would rather keep its STAB of Earthquake
over Counter, as Counter discourages it maintaining bulk and longevity, which, seeing as Donphan wants to maintain as much bulk as possible, I would stick to EQ (not to mention EQ is your only means of checking Terrakion).
On Gyara, I would use Substitute and Bounce
over Taunt and Ice Fang / Earthquake. Its much more aggressive as a sweeper and it can sweep sun teams easier given you get an early set up (and bounce is also resourceful for hitting Venu, as well as forcing Keldeo out). Substitute should not break from Tenta's scalds so in a way you don't need EQ to set up on it (as you can set up more DD now than being forced to just EQ and not get enough speed to outspeed Pokemon x).
That's it from me. I wish you luck!
Sets and Nitpicks
Ice Beam over Psychic and subtract 24 Evs from HP and put them into Spe
Run 248 Hp evs for a better SR number and dump the rest into Spe
Replace Scarf Latios for LO Latias
Run Substitute over Taunt || Run Bounce over EQ / Ice Fang
Keep Earthquake over Counter.
Replace the EB set for Choice Scarf