I agree. The most important thing is that your pup is eating. Also very important is that the food he gets the majority of the time is AAFCO for puppies or for all life stages. Ceasars puppy formulas should fall into this category. You can start to mix another kibble in, but if he just wants the canned, he is less picky than a lot of pups.
When he does get older, it would be best to enforce the high quality food issue a little more.