In Pokémon we’ve got the “official” groups (trios of legendaries, fossil pairs, etc.), but there are also those looser pairs or rivalries that feel thematic, like Electabuzz & Magmar, or Zangoose & Seviper.
And then there are the more “fanon” ones, like Clefable and Gengar.

What other duos/trios would you guys put together yourselves?

Picrel are mine. I always thought Clawitzer and Escavalier fit perfectly as a team: both insectoid-looking (yeah, crustaceans are basically bugs), similar size and shape, one built for melee and the other for long-range. Dream squad.