The Scout moves far ahead of the Teuton troops in order to get an impression of the enemy's strength and his villages. He moves on foot, what makes him slower than his Roman or Gaul counterparts. He scouts the number of enemy units, resources and fortifications.
If there is no enemy Scout, Pathfinder or Equites Legati in the scouted village, the attack remains unnoticed.
Check the part that says: "the attack remains unnoticed". Maybe, if there is a scout, pathfinder os equites legati there, they will engage in combat, who knows.