Bingowings said:

King Arthur is King Arthur because of the blood of his father yes but that's because authority is passed through his family not any particular abilities.

King Arthur is good and swinging a sword because he was squire to his step-brother and trained by his step-father (both trained knights).

Now you can still say his family (he and his father) was good at sword fighting, can you? Both were good at sword fighting, period. It would be an observation of facts that doesn't have to do anything with any kind of inheritance...

Skywalker family was strong in the force. An observation of facts - Luke was strong, Liea was and Vader was. The sentence itself doesn't mean it was inherited. Yes?