Peasant levies were not exactly the norm in medieval warfare. Kings and lords all had personal armies of retainers, vassals and men-at-arms who were well-equipped professional soldiers. Depending on the time and place in question you might see the levy used to augment this force, but even then, in many cases these conscripted troops were also trained specialists - English longbowmen for example.

Peasants were generally only conscripted when they needed to defend their hometowns, or nearby areas. They rarely traveled with actual military forces.