I wouldn't mix raw and cooked meats in the same meal - appreciate your don't want to bring on a pancreatitis attack but the two will take different times to digest which can cause issues with wind and discomfort for your dog.
Most of the pre mix raw foods contain all the nutrients and bone your dog needs. We are finding that ours get hungry on Natural Instinct so bulk out with veg - today they've had carrot, Apple, pear, kale and sweet potato with NI beef.