>>53520714When writing, remember that every trainer in the group introduces a multiplicative number of pokemon, which quickly becomes problematic if they're supposed to matter at all. To be practical, I would keep it to two trainers at most. In realistic terms, a group of 2-4 trainers is probably ideal for traveling safely, carrying supplies, and training with a selection of sparring partners. The big drawback to traveling in groups is competing for rare catches. Many stories gloss over this by merit of having conveniently specialized companions, but if rare is actually rare, there would be a lot of tension over who finds or gets to catch them when they appear. Getting a little too lucky can destroy relationships quite easily, as many lottery winners have learned.
There's also room for people to have pokemon without being real trainers. Someone who travels can just keep one or two for protection and companionship without collecting more or battling competitively.