Quoted By:
After beating all the trainers before Cinnabar(except Sabrina and Koga) my team still feels a bit underleveled, but I decided to go for Koga anyway(since Surf means Cinnabar mansion grinding). There is actually a reason why I favored Birdbrain a bit in terms of leveling, and that reason is Agility.
I decide to be an asshole to Koga. I send in Shroomed first, putting his first Venonat to sleep(he uses X Attack on it).
Then in comes Fearow. I spend 6 turns setting up double team(Venonat awakens 3 turns in or so, but can't land a hit). I finally go for Agility(to make sure I won't be outspeeded by his Venomoth). Birdbrain then proceeds to Drill Peck it's way to victory, taking no hits.
Reason I went for Koga and not Sabrina is that an unlucky hit from Venomoth was way less likely to end Birdbrain than one from Alakazam.
I also had more faith in being able to turn the situation around with the rest of the team if Birdbrain did go down against Koga.