"Run! Run!" The Royal Zodiac Snake Soldiers told the Pandarens to escape the incoming artillery that was coming from the inner walls. As a veteran of the battlefield, the Royal Zodiac Snake Soldiers roughly knew where the artillery attacks were coming from and the approximate location where they would land.
Even though they knew that the Pandarens had very little time to run away from the attack, they are cultivators and should be able to at least escape or bring up a chi barrier to protect themselves.
At the same time, Se Chang Chang and Hou Fei had decided to clear the outer walls while waiting for the equipment they had purchased to be put to great use. Unlike the Pandapolis defensive, the Royal Zodiac Snake Soldiers were on the offensive but they required a foothold for a counterattack as they realised that there was no proper base for them to deploy, rest or assault from.
