The thing is that all dynasty names and shields are already there because if you are High Lord or above you can invite a masterless warrior to your court and He will have a generic dynasty and coat of arms. When you let's say, invite a man good with words and make him a noble he will not take the same generic names and coat of arms he will just take "of Winterfell" as a dynasty name for example. My point is that a newly made noble should take the same names and CoA as a masterless warrior would get.