Not sure if this has been brought up but the flag for Articuno is tied to the contest hall so
capturing or defeating Articuno will result in you being unable to get any ribbions.
My soulution was to remove snorlax event and use his flag. Then pass snorlax off on a trade character.
I also have created, and inserted, overworld sprites for Kanto starters, Jarichi, and Eevee if you want them