I don't like the usage of Substitute on Politoed and Volcarona. Politoed needs all the health it can get to aid in winning the weather war, and randomly losing 25% HP is not something you'll be glad to do. Status protection is nice and all, however is kinda unnecessary for an offensive set since you either deal a whole chunk of damage to your opponent, or just run away if you can't do so. For defensive sets, where status protection could work, you have Refresh as superior option, that counteract also TSpikes, and allows you to Toxic things as they status you and then laugh in their face and Refresh. So, in light of this I would change Politoed to a defensive variant
. This will allow you to absorb more handily physical blows (and special too, thanks to Politoed's respectable base 100 SpD) while sticking around longer to aid in the weather war. Politoed can help your team a lot also with its supportive options: Perish Song is a full stop to Baton Pass teams, Refresh can work to stick around longer, Toxic and Protect can stall the opponent for a while, and the second is incredibly useful against Scarf Genesect leads. You won't miss the offensive prowess of your set too much, since Thundurus-T, Starmie and Volcarona will be always ready to wreck havoc in a now-longer-lasting Rain.
Politoed @ Leftovers | Drizzle
Bold | 252 HP / 252 Def / 4 SpD
- Perish Song
- Protect / Toxic / Refresh
- Toxic / Refresh / Protect
On the Substitute on Volcarona topic, yeah losing another 25% after taking 50% damage for SR, and not having reliable recovery seems a very bad option. Of course you are running a Spinner, however Starmie is not immortal and can be Pursuit trapped by TTar and Scizor (which can both survive a rain Hydro Pump barring crit, and OHKO with Pursuit). I'd suggest to run a third attack, namely Fire Blast, instead of Substitute
, to help you killing Ferrothorn in rain, which would otherwise wall you indefinitely and Thunder Wave / Leech Seed / do some other nasty things. Fire Blast also allows you to hit hard Genesect, which would otherwise survive a +1 Hurricane and U-Turn out or kill you if you're weakened enough. Yeah, and you should run Timid
too, since this allows to outrun ScarfSect at +1 and eliminate it, while outrunning all non-scarf Genesect regardless and OHKO them with Fire Blast.
Another interesting option is running Recover on Starmie
. While an offensive set is awesome in rain, your team is extremely weak to Rocks, thus Rapid Spin support is vital. I won't recommend outright a defensive set since you seem to like Offensive Starmie a lot, however giving up Ice Beam for Recover seems a reasonable choice, letting you hit hard all the spinblockers anyway with Thunder / Hydro Pump and allowing to recover health lost for hazards, Iron Barbs and other sources of residual damage. Losing the ability to hit Dragons is indeed annoying, however with the combination of Defensive Toed, priority from Dragonite (on that topic, while your justification for Aqua Jet is indeed interesting, you should at least use something else to gain more coverage instead of Waterfall, since two Water attacks are extremely redundant; Superpower allows you to not get completely walled by Ferrothorn, for example, and at +1 in rain you 2HKO Genesect anyway with Aqua Jet alone after SR, or Superpower + Aqua Jet regardless of stat drops) and useful resistances from Metagross, you shouldn't have too much hassle checking them anyway.
Hope I helped somewhat. Good luck for your team.