Both the human and orc army divided their armies into four sections. Center vanguard, left-wing, right-wing, and reserve. The one that had moved out to clash was the center vanguard from both armies.
When the two vanguard armies clashed. The sand cloud that followed the human army also slam into the orc army, while the sand cloud caused by the orc army was blown further back as the wind was blowing westward in this area. Since the orcs were facing against the wind, the sand hit their eyes and caused them a short term of blindness.
The human army capitalized on their enemy's sudden loss of visibility and get the first strike. Even after the orcs had removed the sand and managed to open their eyes, another wave of sand cloud hit them again as the wind continued to blow. John had instructed the rear part of the advancing vanguard to keep moving to churn the sand up into the air.
