>>32502352The only example of non-uniform sizes in the games are, to my knowledge, the various fishermen that ask the player to bring large Magikarp, Barboach, Lotad, etc..
When it comes to sizes, I much prefer the anime. It has more opportunities to show ranges in size, with stuff like Nurse Joy's giant Magikarp, or all the different Charizards hanging out around Charicific Valley. I always figure that the Pokedex just gives average height and weight.