What food would you suggest? Ingredients aside, how important is protein content?

Looking at Wellness Indoor Health, the crude protein content is less than 30%. Comparing to Purnina One Indoor Hairball and Weight Control (which is probably what I would switch to had this allergy not occured) has 38%. Fat is higher in Wellness at 13% and Purina has 8.5%.

Blue Buffalo is higher with the protein at 34% but super high in fat at 18%. I also feel like they're biased as I did the "True Blue Test" against the Purina One and it said that Purina One doesn't have real meat as the first ingredient - which it does. So that tells me I can't believe the results. But I know it's grain free, so it has that going for it.