The ethics involved are a very important consideration, included in the ethics are the points regarding conflicting construction of the breeds used, in this case Yorkies and Chi`s.
The ethics can not and must not be pushed aside, they are a massive part of it, and must be included in the decision anyone, including the OP, makes when deciding to go ahead or not - their happy - or otherwise - future with a new dog depends on it. Too many just don`t realise the implications and don`t research enough, education is key regarding all potential dog ownership - and that includes considering the ethics of the breeders people buy from.