I think that just like any being there is a range of behavior from mellow to manic. Each puppy will have it's own personality. Buster is on the mellow side but his friend Roxy is hyper. Puppies like kids will push boundaries and need to be trained early to stop bad behaviors. By training I mean by positive reward training. I have seen many a post on YT dealing with aggressive Yorkies that nip and attack. Maybe these YT threads on aggressive Yorkies will help the OP find ways to help her new puppy.
https://www.google.com/search?q=aggr...w=1016&bih=562