>>24616780Klink and Koffing would make sense as freak accidents, as Klink suddenly showed up only one hundred years ago in canon, and Koffing looks like an explosive.
Magnemite may be natural though, since they're shown participating in the Kalos war alongside AZ's Floette. The technology back then seemed less polished visually than the sleek Magnemite line (Golurk, Ultimate Weapon, etc.), so I feel like they might just be a weird metal creature like Klefki.