I guess I should have explained a bit further, and wrote as a matter of opinion.
Beast, is used a term to describe all three of the legenderies, as it would be really weird (inappropriate, really...) to call them all a certain thing, they all have different traits. For example Raikou is considered a felines (maybe a tiger), Suicune is considered canine. So yeah, it's a sort of classification of all of them. But yeah, not every thing needs to be classified anyway, it's just using common sense. (not directing that to you)
Also, isn't Crown Beasts a bit of a clue? I mean, "crown" could just be a term for "Shiny", so stand alone, Beasts...? (That make any sense?)
This seems pretty fun, I like debates. (The reason why I joined this forum, just try not to get out of hand?)