I'm not a big fan of higher-carb / high-corn type kibbles, which is what RC is -- I think it can just cause too many problems in dogs later down the line. I'd rather see dogs on a more species appropriate diet where the protein is more prominent, as should be for a carnivore. Also, allergies in yorkies is just notoriously ridiculous at this point in the game, so that's just another reason I steer away from carb-rich/corn-rich diets....those ingreds can be so irritating to an already activated immune system.
That said, it doesn't mean I think RC is a "bad food" - I just don't think it's the right food for the majority of dogs. Many, many dogs here on YT do just great on it. Others do not. (which could be said for almost any food, btw
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As for dogfoodadvisor, use it as a tool in your learning arsenal but don't view it as the end all be all -- it's written by a dentist as a hobby/side project. It does have some decent info available, though, for learning purposes in some areas. It's a good place to learn some things about individual ingredients.