I'm going to turn in a nintendo switch knowing one of the joy-cons drifts sometimes
Why are you going to turn in the Nintendo Switch?
I want to be able to claim the warranty in order to have two new joy-cons.
Claiming a warranty on your Switch in order to get extra joy-cons is deceitful, and essentially stealing. You shouldn't try to cheat the company out of merchandise by lying about the product.
It's not stealing if Nintendo sold me a bad product.
You still shouldn't turn in something that is broken and claiming it new. It's better to get a new set of controllers.