Is it just me or is it easy to forget that a lot of Gen 2 Pokémon are from Gen 2.

Since Gen 2 did a pretty bad job at featuring a lot of their Pokémon and featured more Gen 1 Pokémon I find it very easy to think a good amount of Gen 2 Pokémon aren't from Gen 2. Some examples:

Houndoom and Azumaril are pretty well featured in Gen 3 and almost seem like they came from that region but they are from Gen 2. Houndoom can only be evolved from Houndoor in Gen 2 and found only on Route 7 at night. Azumaril can only be evolved from Maril in Gen 2 and found mid to late game.

Piloswine seems like it is from Gen 4 or Gen 6 but is actually from Gen 2, can only be evolved from Swinlub and foundn mid to late game.

These are some examples and there are more, just to show that Gen 2 didn't really showcase the new Pokémon that well.