Yup, I've trained both a Gumshoos and an Alolan Persian before! Admittedly, I would have never thought to use either of them if I hadn't been playing a nuzlocke on Moon with one of my friends. Gumshoos was quite powerful in the early game which surprised me because I've always had the idea that the normal Pokémon on the first route are subpar when it comes to battling. Alolan Persian was also fun but I found it kind of weak compared to my other team members by the time I reached the Elite 4.
I think if there's one thing that I appreciate about nuzlockes, it'd be for showing me Pokémon such as Gumshoos and broadening my mind on all the possible Pokémon I can use in-game. You really can use anything on your team in-game. :D