Well said. The idealogy does indeed transcend simple domination for domination sake. The Sith ofold may have been cackling maniacal zealots, but the Banite Sith evolved into something more sophisticated. As you mentioned, they labour collectively to overthrow the Jedi at some point and that is enough for some lords in the lineage. For example Vectivus amassed wealth from his mining operations and most probably added this to the Sith's collective resources for the on-going underground grand plan. We know he then surrounded himself with friendsand loved ones, probably trained an apprentice and was happy to hand the legacy over to the next successor. I think of it as a relay race in some ways, each leg hoping to gain some advantage over the competition whilst the reinvorgorating the cause with fresh energy offered by the succeeding Dark Lord. Each Master has been the forebear of the legacy that achieved success.