Idk what trainer classes are

All I know is if there are Steel or Dragon focused ones, those are my favorite

Trainer classes are the trainers you find on the various routes of Pokemon games

Gen 4 Hikers as they are canonically the most powerful beings in the Pokémon universe

Um, does James-class count?

I mean, you do fight him in Let's Go and Yellow. Sure, James-class counts

Nice.

My favorite is James-class xD

I can't remember but I'm really sure there is a clown class and if so then

If not then Hex Maniacs I guess

I go with the Pokemon Breeder Trainer class since those battles have multiple Pokemon. Gave much exp and are Rebattable