To the mercenaries, claiming the Fortress meant their jobs were completed. However, claiming the Fortress only meant the start for Rhode. After most of the Fortress was destroyed, it's no longer livable. But luckily, after defeating the Demon General, there was massive information on this Fortress and its area reflected in Rhode's construction system. This proved that this system had recognized Rhode's rights over this place. And next, Rhode would need to restore the Fortress and begin rebuilding facilities. In fact, up until now, Rhode was used to the levels of illogicality on this system. He even gave up ridiculing how this system could repair the Fortress by spending gold coins and didn't require any materials at all. Anyway, since things were set this way, there's no point to figure them out.