My personal opinion is that any hungry dog will eventually eat. If you feel convicted to feed a higher quality food, I would just continue to feed it and eventually he'll catch on. The reason dogs like lower quality foods better is because the manufacturers have to spray fat on kibble to entice the dog. Without it, they'd basically be eating cardboard -- nothing but fillers. The food will fill your dog up and yeah, they'll survive but that doesn't mean they are getting a ton of nutritional value.
However, Royal Canin isn't the worst of them either so if you find that your dog absolutely will not eat Orijen then it's okay to feed RC. It all comes down to what you feel comfortable feeding and how well your dog does on it. There is no right or wrong answer. Good luck!
