>>51166380It's just follow typical JRPG monster formula. You start out with early basic monsters that are "animal, but maybe they have a horn or something" and it's usually birds and bugs in the forest and then bats in a cave. They'll throw around the tough rock monster early game to introduce the first "tanky" enemy where it's either a resource drain or teaches you that you can't just use your sword and need to start using your mana (Or in this case, you need to use more special elementals and not just your physical attacks).
Then it starts getting more abstract with plant monsters to showcase that it's not just animal-like creatures that inhabit the world, and potentially introduce you to status ailments. Then as you progress, you get even more abstract enemies such as ghosts and living objects (This is where Magnemite comes in).
The late game of a lot of JRPGS will then introduce living elementals (Which I assume is what things like Magmar and Electabuzz are meant to be) and then humanoid enemies (Jynx, Mr Mime, Hitmon-family). The final stage of JRPGs has dragons which are almost always the toughest enemies. Then obvious, the mimic which is supposed to be Voltorb family since the overworld has you picking up pokeballs, not treasure chests.
Pokemon doesn't follow it exactly 1:1, you can find Machop early on and he's a humanoid Pokemon. But it's obvious that when making the game, they were kind of learning from other existing JRPGs at the time and using the formula as a base and then changing things around during development for balance purposes. The only real oddball part is that Grimer, the game's slime, is found at the halfway point in the game instead of close to the beginning.
