I had this exact predicament. I ended u levelling up Pidgeotto. But DANG that fight made me mad! I lost a few times. Ever since then, I've had an OCD of grinding to level 20 before I even leave whatever the first route is. In any Pokémon game.3. Whitney. Miltank. Rollout. When I had Quilava and Pidgeotto and an underleveled Geodude.