Team building

[PhantomUnderYourDesk]

I have chosen Gararewl to wear down opponent's Nucleon due to its Steel typing. So, I prefer a Pokemon which resist to ground types. I take Choice Scarf Pajay to outspeed Nucleon and others Pokemon.
Is it a good idea ?

I think that's indeed a good idea, yes.

Humm, if you are searching for offensive Pokemon with a resistence to Ground Type, how about Coatlith? That grassy dragon's natural Ability Leviate outright nullyfies Ground Type moves; and even if the foe manages to outsmart that, moves of that Type only do 1/2 damage. That, and Pajay's rather frail (I heard/read) and super-vulnerable to Stealth Rock and generally Rock Type moves, which Coatlith can handle well due to his partial Grass Type.