It's very good that you're doing lots of research to learn the personalities and temperaments of each breed because if you're getting a large dog to go along with a 1.7lb yorkie, then you have to make sure they're not going to hurt the yorkie by accident from being playful. It might be better for you to get an adult larger dog who has already gone through the puppy stage, so the yorkie doesn't get hurt.
I know many people on here have large breed dogs (including boxers and rottweilers) with their yorkies and they all get along
Good luck!!