There's going to be a lot, but someone is only going for six.
Kanto has added a group of obsessives for Let's Go Pikachu and Eevee.
"Master Trainers", trainers who specialize in a single Pokémon, have been revealed for the November 16 release. These Masters will be found around the region and will be signaled by an icon of the Pokémon they represent appearing over their head.
In order to claim the "Master Trainer" title for a Pokémon, players will need to defeat the Master with their own version of the Pokémon in a one-on-one match with no items.