one thing i always wondered about the sith is that Darth bane created the rule of two and the movies focused on that lineage but with many of the books talk about planets ruled by the sith like korriban or species that used the dark side like the rataka but with all those sith artifacts and holocrons lying and thousands of Jedi through out the galaxy one of them could stumble upon them and convert to the dark side how would that have played off with sidious, plaguies or bane if they finds one these peoples would they immediately hunt them down, wait until they pose a direct threat or try to strike a deal with them or use them to their advantage
I'm not an expert on EU (the bulk of it is (Mod edit: not allowed) in my opinion, so I mostly don't take it seriously), but this is MY theory: I think that Bane was aware of this problem and made sure that the Sith knowledge or teachings would only stay in the hands of a master and an apprentice. So, if anyone stumbled upon some Sith artefacts and wanted to become a Dark Jedi, he wouldn't pose any real threat to the existing order as he simply wouldn't be able to acquire enough knowledge. He could have gathered enough power to be considered a threat, in which case I think that the real Sith (or even Jedi for that matter) would sense a disturbance in the force and hunt them down eventually. That's why Palpatine and the Sith before him were so secretive - they were strong enough to conceal themselves from the Jedi and simply needed to forge a grand plan to overthrow the existing Order. In short, I think th
I believe that by the time Zannah had taken over as the master, Bane had already started a library of Sith works and holocron teachings. And in terms of your post, in the EU Bane actually visits Rakata Prime and finds the Revan holocron, as well as the Nadd holocron in his tomb on Dxun. And, Bane destroyed all of the Sith of his time, and trained at their academy on Korriban, so it can be reasonably assumed that he went back there and took most of the knowledge for himself once he was flying solo. Finally, Bane visited the Sith tombs on Korriban as well and searched for lost items there, but found nothing. So I would say that by the time the Bane lineage had begun, a lot of Sith history and teachings collected by Bane himself and by the Sith before him would have been in his possession, making it extremely hard for someone to simply stumble across one without actually knowing it's location (and very hard to actually get it once if they found it). And I forgot his findings on Tython, also.
It seems to have varied, though such Dark Siders of course make a nice pool for potential apprentices (or replacement apprentices) or as a source of ancient Sith knowledge. Palpatine did however recruit a surprising number of them as minions over the years, employing them as Jedi Hunters, Governors or “Truth Officers”.