Forum:KB:Sith Triumvirate & the true Sith?

If Darth Sion was aware of the existence of the 'true' Sith Empire, why didn't he and Nihilus attempt to somehow get in touch with them? If what they wanted was power, why didn't they journey to Dromund Kaas, where they could have embraced the full legacy of the Sith, and instead decided to stay with a bunch of weak assassins and droids that were left from Malak's empire and that had so little to offer? Thank you.