The originality of a cartoon animal / random object with exaggerated features / big eyes / being on fire is the most subjective thing this franchise has ever produced.
If a Mystery Dungeon game can work with Chocobos, a fat man from Dragon Quest, the world's most stereotypical Samurai and previous generation Pokémon there's no reason for it to be any different with the new ones.
That doesn't make any sense. The first Rumble came out only a month after the Japan-only Wiiware Mystery Dungeon games.They're series made by totally different people.