Cell, the regular Acana line is lower in protein than Orijen (eg. 29% for the regular adult formula). However, it's still in the mid to high range in comparison to feeding raw or a home-cooked diet. Acana could be an option for you or maybe you can consider home-cooked if raw didn't work out for your dog.
Something else to think about when switching to a lower protein kibble. Commercial kibble with a lower protein content has a higher carbohydrate content and, imo, a diet too high in carbohydrates is not appropriate for dogs either. It would seem the only way to feed less protein is through raw or home-cooking
Yet something else I was thinking about...when discussing low vs. high protein, that's in relation to kibble only. I would consider that fresh or cooked meats contain the appropriate amount of protein and amino acids because it's fed naturally (whether cooked or raw). In that case, the 20% average protein levels found in this method of feeding is in the normal
range, not in the low range. Make sense?