After Qin destroyed Zhou, the realm lost its nominal authority and entered a chaotic era of infighting among various kings.
In this era, the feudal lords governed independently. There was no longer a nominal Son of Heaven, let alone any authority to "use the Son of Heaven to command the lords."
Before the appearance of the Imperial Jade Seal, the Nine Cauldrons represented authority. However, the Nine Cauldrons had been seized by Qin after the fall of Zhou, and the feudal lords would never acknowledge that.
Chapter 246