"It's too bad that "Size" or weight is such an issue......I love a true well bred Yorkie"
You said it. And a well bred Yorkie would closer adhere to the standard. Even the best matched mates can sometimes produce off sizes, but this doesn't occur often and a good breeder would be wise to be careful of pairing those two again in the future, or holding onto it longer until they can spay/neuter the dog themselves rather than relying on the clientelle to do it.
And w/ that said: