Why bigger guns weakened German destroyers

German destroyers carried guns large enough to threaten cruisers, but the design paid heavily for that theoretical reach. Their slow rate of fire and the movement of a destroyer made them difficult to aim against small, agile targets. A powerful shell might pass through an unarmoured destroyer, while smaller enemy guns could still damage the German ship because it carried no comparable protection. The armament therefore offered little advantage in the destroyer fight that the ship was most likely to face. The design lesson is to match weapons to the platform's actual opponents and combat role.