In ancient history, the most powerful, efficient and developed empires developed ways of moving organized units of troops from one place to another on the battlefield, without individuals getting mixed up with other units. Otherwise, as masses of people maneuvered amongst each other individuals would get lost and end up having to attach themselves to any old unit. A system of flags was developed so people could identify their own units (and side) on the field and make their way to their correct flag bearer if they got separated. But sticking to "formed up" squads was better, forming a box of men who moved as a single body. Overall it meant command systems were effective - men stayed together and could be commanded as units. Josephus, a first century Jewish historian, testifies to the superiority of Roman discipline, and part of that discipline was an ordered method of moving formed up squads from one place to another. This discipline facilitates effective realisation of tactical man-management, and the result is a superior fighting army.
