Crawlers who prefer to stay out of direct fighting and instead track the war's big picture from base.
Carl's Prisoner Orders reveal a piece of the crawler army's structure that never appears on the line. When an enemy mercenary is killed and looted under the Safe-Looting Protocols, the body is kept and the incident reported to a superior officer, who passes the information back to base — where a group of crawlers who prefer to stay out of the direct fighting keep track of the big picture.
Their existence gives the Land War an intelligence and logistics apparatus behind the trenches, staffed deliberately by crawlers unsuited or unwilling to fight, and made necessary by the volume of information Battalion Structure generates.
Non-combatant crawler staff maintaining the army's intelligence and record-keeping from base.