Concerning the storyline part, this was not really what I was talking about.
It's more like I wonder if the Pokémon monsters appear in a certain order through certain games.

As an example, I'd probably say the first part should have Bulbasaur, Ivysaur and Venusaur, as they are the first, second and third monster.

The first monsters in the first game, and so on.
Or perhaps most monsters are present in most games?
I forget.