Monsters reclaiming Ancient Ruins Spaces was not an unusual occurrence. Long before Zhou Tian had even reached Pope Level strength, he had already started engaging in such activities. Although he had Pope Level combat power when he truly reclaimed his first Ancient Ruins Space, nevertheless, Zhou Tian's early experiences showed that as long as the Monsters found the right target, regardless of their strength, there was hope in reclaiming those spaces.
Since Zhou Tian could reclaim those Ancient Ruins Spaces when he was at Pope Level strength, it was definitely much easier for Beastman sub-Bosses, now at King Level standard, to consider reclaiming those spaces, even though not all his sub-Bosses had his foundational abilities.
If Zhou Tian could reclaim Ancient Ruins Spaces while he was still at Pope Level, then if those sub-Bosses couldn't do the same after reaching King Level, it simply meant they were too incompetent.