The way wars were fought changed greatly over the decades, beginning as clashes between armed mobs with little thought to tactics and even less to overall strategy. The idea was to fight over whatever the main issues at the time was with no thought of the long term repercussions.
The process of waging war changed with the advent of newer and deadlier weapons being introduced into the theater of war.
The change from mobs of foot soldiers charging each other on the battle front changed to one where the foot soldier was relegated to an afterthought as the heavy cavalry of the Middle Ages took the spotlight, and took the heavy lifting away from the infantry.
The common foot soldier was at a distinct disadvantage when faced with a charging knight in full armor astride a war horse wearing an armor of its own.
The evolution of war also saw the peasant army slowly change into a paid professional army that was more interested in spending its pay than fighting needlessly for a lost cause.
The introduction of paid armies also meant that for the first time, commanders actually had some control over the troops in their armies and were able to execute their war plans and exert influence the outcome with advanced tactics and battle strategy.
This control and the benefit of having it were seen in the Battle of Crecy in 1346 when the French Army outnumbered the English Army by around 4 to 1.
During the ensuing battle, the French army seeing the advantage in numbers they had over the enemy proceeded to charge the English army who exercised command and control of its forces and let the French commit themselves to battle before employing their tactical maneuvers to virtually surround the French mob, and deliver a resounding defeat that proved that tactics and strategy were far more important that numbers alone.