My Yorkie Pyppyn is nearly 10 months old, 5 1/2lbs and in excellent health, considering that in October he survived a
viscious attack from a 90 lb. Akita!
When I got Pyp as a 4 month old pup from a breeder in New Jersey, he was raised, as all of her babies are, on
Mini Royal Cana kibbles. A great product which, like most Yorkies, he eats with gusto some times and at other times, needs some "prompting". I have found it better to regulate and adhere to a schedule when feeding him as this has made it easier to house-train him. By sticking to a schedule, I can
almost predict when he needs to be taken outside to potty. He
usually doesn't disappoint!

When I left food & water out for him to feed at liberty, it was very difficult to anticipate outside "potty" calls which quickly became indoor messes

I guess if I elected to paper train him, the feeding at will might not be an issue.
I have considered the pros & cons of wet food vs. dry food and have come to the decision of basically giving him his dry kibble in the morning, a little yogurt/acidopholis in the afternoon (1 tsp worth) and a mix of kibble
and wet for dinner. One small can of wet food lasts for several meals. Every now and again, I'll soft-boil an egg and crush it up (shell and all) and add a little to his breakfast or dinner. His coat is amazing.
Now that he is older, I have gone down from three meals to basically two a day. This also includes the odd "treat" (especially
after he potties outside), and I provide him with water after each meal. I keep him very active - in fact, I often have to draw the line with my little macho man as, given his druthers, he'd play fetch non-stop for HOURS! And to my amazement, this little tyke enjoys really LONG walks.
Just thought I would share my feeding routine with you all. I also strongly recommend the brushing of a Yorkies teeth, which I do 3 - 4 times a week. At first, Pyp was no fan of this, but he has come to really enjoy it! I do feel it is important to feed kibble as it promotes healthy teeth and good oral hygiene. I would not think it great to only feed wet or canned food.