If the difference in strength was too great, those players would surely be completely annihilated once surrounded by the monsters, and even if the monsters did not manage to fully surround them or did not hold much of an advantage in strength, most of the players could only manage to escape in part. Overall, at that time, they were still at a disadvantage under the hands of those monsters.
Given Zhou Tian's ability, his series of arrangements back then naturally led those players to suffer quite a bit at his hands. Even though the players managed to kill many of his lesser monsters, Zhou Tian's strength not only remained unweakened but actually grew significantly at that time.