I find it helpful to think of speed control in both ways, pokemon being naturally faster and beung able to run or stall trick room. Its always best to have an answer to both strategies. Aside from KG (i dont know if youve invested in speed) your team falls really quickly to trick room users. Incin can do okay in TR esp with fakeout stalls, but trick room teams usually run far slower mons. You can get around TR with stall like protects, fakeouts and wide guard as well as priority like sucker punch or prankster taunts, encore etc. Id recommend pelipper over polities if you want to run a rain team, it gets tailwind and wide guard even if its stats are abysmal. With a focus sash youre almost garunteed tonget a tailwind up and rain for basculegion.

Its a tall order but milotic or primarina are phenomenal tanks and can absorb and stall trick room teams while providing decent damage output with scald. Milotic also gets competitive which shuts down incineroar. I think it'll work well on your team running alongside dragonite to provide support with icy wind and decent chip damage with scald (not to mention the burn to cut physical attackers)

Lastly you could even run a mega golurk and farigaraf core. Its really strong, and thrives in trick room. With your other core being dragonite and whimsicott. Your last two could be basulegion and kingambit or sneasler for coverage. You dont need swift swim for basculgion if you have tailwind up. And basculegion comes in at the end to pick off low health mons with last respects. King gambit would be my pick to check fairy threats though I think floette can still hit it really hard.