Dodrio - its the superior birb for a FR/LG playthrough
- Dodrio has a higher BST than Fearow, while surpassing its Attack stat by 20 points.
- Doduo is available right before the Grass-type gym, making it very easy to level up and evolve; hence, justifying its spot on a team.
- Doduo learns a fantastic Normal-type STAB move in Tri Attack, while Fearow forces the Return TM.
Dodrio @ Anything / Soothe Bell (if using Return) / Leftovers / Silk Scarf / Sharp Beak / Cheri Berry / Pecha Berry / Persim Berry
Ability: Run Away / Early Bird
EVs: 252 Atk / filler
Adamant/Jolly Nature
- Fly / Drill Peck
- Tri Attack / Return
- Steel Wing (TM 47 - Safari Zone)
- Filler
You can catch multiple Doduo for the preferred nature, while Attack EVs can be gained by defeating wild Doduos or using the VS. Seeker on Biker Isaiah/Raul/Jamal/Seek/Corey on Route 17.
The only thing Fearow seems to have over Dodrio is that its available earlier, but that doesn't matter as its weak to the 1st and 3rd gym, while only really shining in the 4th gym when Doduo becomes available.
It might be at a higher level than a newly caught Doduo, but a level ~25 Doduo can single handedly clear Erika's gym,
simultaneously making it catch up with the Fearow's level.
Source: Experience and the pokedex pages for the respective Pokemon
Hope this helps!