Basil Jaak's plan was very meticulous. After contacting Roger, Basil personally disguised himself to scout Yellow Sand Town.
As the hub linking east and west in the West Wilderness, Yellow Sand City's defense was incredibly tight. Even more so because recently Basil Jaak's army had arrived, causing Yellow Sand Town to shut its gates, allowing no one in or out!
Under such rigorous defense, Basil Jaak's attempt to capture Yellow Sand Town became quite tricky.
After observing for a month, Basil informed Phoebe and Brain Fitzell to hold off on attacking Yellow Sand Town and instead target Stone Copper City, over six hundred miles north of Yellow Sand Town.
Of course, Basil also sent a message to Roger, who was closer to Yellow Sand Town, ordering her to secretly train soldiers and remain still.
The attack on Stone Copper City was naturally a feint.