Zeroth is in his own world
Emile is in some sort of Final Fantasy-esque world
The Toxes are Pokémon in their own world
The Reindeer are in their own world (but could arguably be in the main one)
That leaves the “normal” OCs Rowen, Atlas, Roscoe and the 3 Scots. Rowen, Roscoe, and Atlas interact plenty in their day to day lives, and I have a little headcanon of Rowen and Atlas vacationing to Scotland and meeting the farm trio there, but that’s about it!