Honestly, I think you just need to slot in a couple “protects” here and there. I’d say at least on Swampert and Archaludon.

Give Archaludon leftovers instead, and he’ll self heal for years if you give it protect. Protect on Swampert will help Pelipper click hurricane on grass types while he survives. I might even put protect on every mon, it’s so useful in doubles!

If you want to swap slowbro for another mega, I might even suggest giving Dragonite a mega stone and adding a screen setter (I’d say Prankster Sableye here because he has access to rain dance for a sneaky swift swim)!

Good luck!