the reason why in gen 2 gym leaders don't use that many johtomons, and the reason a few of them are postgame locked is because they are supposed to be newly discovered species.
It makes no sense in a lore perspective but it explains a lot for us.


https://www.youtube.com/watch?v=_-K-sVn8Iko&ab_channel=TheOfficialPok%C3%A9monYouTubechannel
>8:13
>steel type pokémon are just being discovered