The Peditata was a type of Auxiliary infantry who assisted in assembly of fortifications and buildings that supplied the army in camps and forts. The Peditatas were assempled into a 480 infantry cohort. It was organized into 6 groups of 80 men each with a full complement of officers and organizers. The Peditatas were based mostly in England, where they filled the ranks of the garrison there. The Peditata in your game is a weak unit, but is able to build and repair buildings and fortifications. If properly used on the field of battle it could turn the tide.