Inconsistencies or Retconning? Edit
In the Tales of the Jedi: The Golden Age of the Sith comic series it's mentioned that there were only 7 worlds in the Koros System, not 9. However since it was mentioned in relation to the Unification Wars, they may have only been talking about the planets that were inhabited. Therefore if 2 of these 9 planets were uninhabited, it would make sense.
Also another planet, Kirrek, was named as one of the planets of the Koros System, and took part in the Unification Wars, yet it's not mentioned in this article at all. However on the Kirrek page it claims it is part of the Empress Teta System.