[matese]

I think you mean he is a Parti yorkie, If Mickey has various colors white, brown, gold and black hair that is called a Parti yorkie. Your question of how my oldest yorkie and this one can be the same breed and look so different? If you are referring to hair color do you mean they look different because of the color of their hair. When you selected Mickey did you see the puppy in person or see his picture, you make it sound like you purchased a puppy sight unseen. Parti yorkies are not traditional tan and grey or tan and black, Parti yorkies always have mixed colors, the basic color being white with splashes of black, brown and maybe some tan or gold. At 11 months old it is to late to get his ears to stand up, this should have been done when you first got him, shaving the hair off his ears would have been suggested to do, the less weight on their ears helps the ears to stay upright. I had 2 yorkies with floppy ears, nothing wrong with that they are still cute.
Can you post a photo of Mickey, with YT pics they have to be 200 KB or less, you may have to resize the photo to post it.