Lets have a talk about regional availability and the native regions

would the possibility of starters from previous regions showing up be too outlandish?
they come from somewhere, unless all the professors are friends and happen to have starters in their safari

Well I think the Tailow line is the regional bird if Hoenn because it's rarer.

Wingull can be found in every region I think

I don't like the fact that you can't catch that Corpish the first time you got to Mauville City...