The decision of the peak Profound Immortal from the Da Wei Sect, under the current circumstances, was the most prudent arrangement.
The figure that escaped and fell into Jade Lake, without a doubt, could not possibly be Gu Lian Peak Master, but could only be that mysterious immortal who had destroyed the sect.
Should that mysterious immortal not be severely injured and return to the sect, the Da Wei Sect would truly be left with nothing but destruction. Even if that mysterious immortal was severely wounded and perished, this stronghold would no longer be safe, and no matter what, it would need to be moved.
Therefore, it was very necessary to split their forces in two. In the worst-case scenario, they could ensure the sect's lineage would not be extinguished.