Here’s quite a question, how do you think gamefreak decides to place pokemon where they are in the game. For example, some things make sense like placing a claydol in ancient ruins and such, but then somethings don’t make sense, such as placing smeargle among the ancient ruins of alph? Or
I think some more counterintuitive examples must have been cut off the end there. This is a shame, because I actually do think that Smeargle living in the Ruins of Alph makes a kind of sense – Smeargle is (one of?) the only Pokémon who can do something like writing, which is what the whole area is themed around. But in terms of the general process… I think they probably start with a rough outline of what the region will look like, including a few biomes (desert, snow, etc) that they know they’re going to need, then start distributing Pokémon according to a combination of habitat requirements and gameplay concerns. They like to have new-generation Pokémon introduced in a steady stream. Since I think Ruby and Sapphire, when you play through each game, you tend to encounter at least one new species of Pokémon in each major area (except water and cave areas), so that’s clearly something they’re conscious of. I think there are a few areas that are designed with specific Pokémon in mind, like the Ruins of Alph for the Unown, and the crystal caves near Shalour City for Carbink. Brooklet Hill and Lana’s trial in Sun and Moon are clearly designed around introducing Wishiwashi. So there must be some degree of feedback between the design of the region and the Pokémon they want to fit into it.