That sounds like you and Buddy had fun. They really do seem to know their own breed no matter what their size
My two are the same, they just love other yorkies, although Coffee has a liking for Snauzers(sp) as well. I love them too so maybe that's why.
My Coffee is BIG, just like your Buddy, and when he meets tiny yorkies, he lies flat on the ground, not on his back though, it's like he wants them to know he will not hurt them. I go to the locol dog shows now and again, so my two are lucky to see "their kind" there.
I hope you bump into that baby again.
Sheilagh