Valor and Prudence

A suspicious fraud who calls himself the Master of Prudence has organized lessons of "sensible valor" in Drezen, charging a tuition fee for the lectures. He teaches the soldiers how to survive on the battlefield, beat a hasty retreat from dangerous situations, and avoid unfair fights. His advice is not devoid of reason, but it is a lot more sensible than valorous. Would it be useful for the soldiers to listen to him?