In the "Battle of the Atlantic," the Germans lost almost 800 of their 1200 submarines (nearly two-thirds) sinking 3,500 Allied merchant ships and 175 warships. http://en.wikipedia.org/wiki/Battle_of_the_Atlantic_(1939%E2%80%931945).
Some 30% these "kills," were accounted for by 30 veteran captains or "aces" who had experience in World War I, while about two thirds of the submarines (800 out of 1200) sank nothing.
One veteran World War I submarine captain was an Austrian named Georg von Trapp. The whole focal point of the "Sound of Music" was whether or not Captain von Trapp would become Germany's 31st submarine ace. (Von Trapp and his wife Maria were real people, and while the "seven children" existed, they were fictionalized by the movie as being younger than they really were, to allow "Maria" to be their "governess.")
Are there any historical accounts or naval doctrines that suggest that "quality is more important than quantity" in submarine warfare? That is, that 100 more "Captain von Trapps" using the same or fewer ships would have been more useful to Germany than 1000 more U-boats manned by random crewmen?