My Big Monster got RC food for kidney problems. He did not eat much of it, because he was too sick to have much of an appetite. Little Monster, who was perfectly fine, ate it if he could get it, but then, Little Monster ate everything.

I got some crab cream from the vet to make it more appetizing.

If it's just to avoid sensitivities, I'd try the other brand (and inform the vet, just in case.)