The Ancient Mansion controlled eight commanderies, and Jing Yan planned to attack all eight simultaneously.
The main target was naturally Flowing Light City, the Ancient Mansion's stronghold. The reason for simultaneously attacking the other seven commanderies was primarily to contain the power of the Ancient Mansion.
Any of these seven commanderies was extremely important to the Ancient Mansion. If the Ancient Mansion did nothing to defend them, the fall of each commandery would cause significant losses to the family. Therefore, the Ancient Mansion had to divide its forces to protect each commandery.
On the other hand, if Jing Yan did not attack the other commanderies besides Flowing Light City, the Ancient Mansion could withdraw forces from these commanderies to defend Flowing Light City.
After comprehensive consideration, Jing Yan and others believed that attacking all eight commanderies simultaneously was most advantageous.