It took a lot of time and effort to mobilize an army. First, orders had to be handed down from the emperor to the general, who then handed down those orders to the lieutenant general, who then handed them further down the line and so on. Once orders were fully passed down, captains would mobilize their squads and meet up with their commanding officers.
And that was just the first step.
There were many different branches of the Shang Kingdom’s military. After informing the officers to mobilize their army, she needed to speak with the officers in charge of logistics. An army ran on its stomach. Not only was rations needed to keep the army going, but good food boosted morale.