much like r/b/y, use nidoking. hes pretty common by viridian city, and has a very good movepool. He could have something like thrash, earthquake, thunderbolt, and surf/ice beam. just an idea, im probably missing something here.

I think the main reason we don't use nidoran is because by the time he would get a good moveset we'd already switch. After a bit we skip gyms 3-6 to get the fossil and go to get kabutops/starmie because they are close to level 45, which around that point eevee would probably be like level 30.