Double post... But I was originally thinking that a coven worked like a large keep, in one building, though including every household member. The explanation above seems more geared towards a whole duchy or small kingdom. So... just for clarification on my part. 

Is the term coven meant to replace the conglomerate of one household/castle/estate, or one county/country/province/land? Errrr, I suppose, does the coven boundary stop at one building's walls(but with the political clout extending farther), or does it encompass multiple villages and towns and cities and high ranking members?