We could limit what's available where to balance it out. Like the more common ones would just be around everywhere, whereas the rarer ones could be in less locations. The only problem is that people are going to want their pokémon regardless and we don't want to make it too painful for their character to get something if they want it that badly.

That's how I caught my Sawk. Maaaang. I hate it but I was so angry I haaaad to.

The lists can always be tweaked! I'll chat with Okami and see if there's something we could move around with this.