There's a world where you switch in Torterra to eat a Charizard fire attack, queue up rockslide and hold your breath that it doesn't have a special flying move in the pocket that can chew up the rest of you.

Torterra absolutely does not survive two fire moves. It likely doesn't even survive a single Flamethrower. It's still weak to fire. Also generally speaking, Torterra is unfortunately just not very good.