>>28184259That's dumb as shit. The reason signature moves were called signature moves was because they were heavily associated with their pokemons. Just because some other asshole learns it, it don't mean it stops being associated with the pokemon in question.
See bone club and bone rush. Everybody still associates it with the pokemon who learn it, nobody goes "bone rush? wtf kind of pokemon learns that?" Ergo, it is identifiable with the pokemon. So, bone rush is marowak and rasta dog's ________ move.