So, since it was already clear, at that moment they basically had no way to deal with Zhou Tian, so the group of NPC demigods of that time didn't need to waste too much time on Zhou Tian anymore. Hence, their withdrawal was not at all surprising.
In fact, Zhou Tian didn't have to wait long; when that faction of NPC demigods returned to the position where their large army was stationed, the group of monsters Zhou Tian had arranged had already automatically dispersed. Although those NPC demigods were unhappy with the actions of the monsters, they didn't stoop to bother with them. Eventually, after casually killing some of the slower retreating monsters, they led the NPC large army away.
Once that NPC large army had withdrawn, Zhou Tian clearly realized that whether those NPCs liked it or not, they had seemingly acknowledged Zhou Tian's ownership of that area. In other words, in the consciousness of those NPCs, they had probably already regarded the area as Zhou Tian's territory.
