Variety is good but by rotating between too many protein sources (and grains for those who feed them), what you would be doing is "boxing yourself in".
Sadly, I have an example.
Ellie eats homecooked and her grains were rotated often. Now she has gastrointestinal issues and some itching (again). She needs a novel carb. I've already used oatmeal, brown rice, white rice, wheat pasta, barley, corn (in kibble that she used to eat), cereal (as treats) and then peas, potato and sweet potato. So, unless we want to go to millet or couscous, we are kind of stuck for an elimination diet. Now she is on oatmeal (again) and sweet potato (again but shouldn't hurt). So we will see.
All that to say, be careful how many proteins you rotate through in case she does need a novel protein someday. If she has been exposed to most of them, she would likely require a prescription diet with hydrolyzed protein. And if she has had anything with "meat" as an ingredients without naming the meat, then she has likely already had four proteins (beef, pork, mutton and goat). At the same time, I'm not saying use the same food forever because you don't want acquired allergies either. I hope this makes sense.
