If Zhou Tian didn't have any other arrangements, even if he continued to sacrifice his Bearmen to further pressure those NPCs, forcing them to utilize other measures would still be a difficult task. As such, knowing full well that his tactics are of little effect, even if Zhou Tian doesn't care about casualties, there is no need for him to deliberately send his Bearmen to certain death.
After the current situation has progressed to this point, Zhou Tian is already contemplating taking action himself.
Zhou Tian realizes that his current understanding is merely of the basic defensive fortifications of the NPC Holy City. When faced with greater danger, those NPCs could likely bring forth defenses that pose a significant threat to him.
If Zhou Tian doesn't want to take risks, the best approach would be to continue swarming the enemy with his Bearmen, despite this method leading to significant losses. However, it would not pose a great danger to him directly.
