About the corn comment...I give my guys popcorn sometimes, they LOVE it! It's unsalted & unbuttered, so it's not so yummy for me.
Corn
can pose a problem when it's given everyday, 2-3 x's a day for years, sometimes for the life of the dog. Some dogs can & do exceptionally well on corn!
Just like people, dogs should be getting different kinds of fresh foods, fruits, veggies, meats, oils & fats (fats are a very important ingredient in a dog's diet). So a raw diet is
not one type of food, proteins are rotated, so are the veggies & fruits. The dog is getting the essential amino acids from all types of different fresh foods.