The most fatal issue during ancient warfare was the backwardness of communication technology. The battlefield could only be divided into small segments by outdated communication, each fighting on its own, which could even lead to situations where they hindered each other.
Therefore, in most cases, the outcome of ancient warfare was decided by battles between the most elite tens of thousands, because these troops were the limit that one commander could control.
Beyond this limit, signal flags and drums completely lost their function, and no matter how brilliant a general was, they couldn't coordinate and command effectively, and additional forces would fail to play their role due to missed opportunities.
