Originally Posted by Fat Longfellow
Dodrio's 20 extra base attack is a pretty big deal. Add the access to better Normal moves and getting Drill Peck earlier and you've got a significantly stronger Pokémon, whereas Fearow is never significantly stronger than the unevolved Doduo.
That said, I think an argument can be made for Spearow in High on its own merits/compared to other High-tier Pokémon. I guess I'd put Spearow in Mid but would be fine either way.
The question is: is Dodrio's 20 extra attack significant enough for a lead? Is Dodrio capable of killing things with Double-Edge/Hyper Beam that Fearow can't? If Fearow is capable of killing the same enemies in the same amount of hits as Dodrio, then Fearow and Dodrio are pretty identical in this regard.
Getting Drill Peck earlier is only a minor win for Doduo, unless the 4 levels between which Doduo and Fearow get Drill Peck is significant enough for Fearow's performance to be an entire tier later. Yes, Fearow is statistically inferior to Dodrio in every regard (except 1 point of special but who gives a shit), but if Fearow is capable of getting the job done, why not?