Right now, the reason for other powers locking horns is mainly to withstand Zhou Tian. As such, before they have absolute confidence to handle Zhou Tian, no matter how intense the struggles among themselves, it's absolutely impossible to take action against Zhou Tian. Thus, the areas near Zhou Tian's territory remained relatively peaceful during the chaotic state of affairs elsewhere, even if the monsters hadn't pledged allegiance to Zhou Tian, they certainly didn't dare to provoke him.
In fact, considering the circumstances back then, Zhou Tian could have potentially expanded his forces several times over if he was willing. However, it seemed Zhou Tian wasn't prepared to do such a thing at that time.
