My Yorkie is on an rx diet and my other pup is on Science Diet Nature's Best.
You will come across tons of opinions on YT which is what makes it fun

, but confusing

.
I did see you mention in another thread that your 5 - 6 pound pup gets a small bag of food every week and a half? How big is the bag? My Yorkie takes a month to finish a 6lb bag of food.