Nicely done! Max has learned the same sorts of tricks that our first Yorkie was able to accomplish, and training him was a breeze. Our current Yorkies are more difficult to train, not because they are less intelligent IMO, but because they have their own agenda and are more stubborn. I know that based on their behavior, like coming to get me when they pooped on the paper so that we can hand out a treat and such. Those types of behaviors were not trained, but they were learned. Distinguishing individual toys by name and fetching on command is difficult. Our male LOVEs fetch, and in a pile of toys, there is only one he wants to play with (go figure). So when he is siting there waiting for me to toss a toy, I may have to go through the whole pile until I get to the one he wants me to toss, so that tells me they definitely know the difference, but getting them to bring you a certain toy they are not interested in is very hard in my experience.
Also, I really like the way you don't have to give Max a treat after every treat. Dogs should not need that constant treating for motivation, but a "good boy" should be enough after they learn the trick.