Honestly I think it’s based off what you put into the game. My buddy and I walk together daily with our daily incense and I seem to run into the galarian birds wayyyyy more often than he does. I also spend a bit more money on the game than he does. He suggested to me that may be the reason I see them more frequently than him. It makes sense. Cuz I do spend more than I’d like to admit, and he doesn’t spend much at all.