I wouldn't worry about his size.. just love him the way he is.. just to let you know that the litter that our Hannah Mae came from .. she had a large brother in the litter.. when we picked Hannah Mae up.. he was almost 3 times her size.. it happens. They are larger, but they are still Yorkies.
Give him big hugs and kisses from Jen and Hannah Mae

, He is so cute.. love the picture with the hat on..