Like @Luplayz said, it's happened before, so it's not really surprising that it happened again. With that said however, I agree with you that I think they should've done something different, typing wise at least. A combination of Dark, Ghost or Fighting (and to an extent Fairy or Psychic) are all types I could see fitting for Zarude (hate the name btw). To me it kinda looks like it was supposed to be in a trio with Oranguru and Passimian, got cut and then they decided on a Tarzan'esque movie, needed a Mythical, went through some old designs and picked that one. I don't think it looks bad, but I just don't think it looks special either.