Once you have completed all of the Break tests resulting from combat that turn and have taken all necessary Panic tests, it is time for broken and panicked troops to flee. Fleeing troops turn directly away from their enemy and run as fast as they can. If they were engaged by several opponents, they flee away from the enemy unit with the highest Unit Strength. They abandon their formation and run from their enemy in a complete rout, blindly scrambling over the ground in their efforts to avoid destruction.
Even though the fleeing unit moves in a disorganised mob, for the purposes of moving the fleeing troops, it is convenient to keep them in formation.