Why surface raiders could disrupt whole convoys

Submarines and aircraft could take repeated bites from Axis traffic, but a surface force could destroy a convoy in a single concentrated attack. The distinction is between losses that accumulate gradually and a sudden loss large enough to frighten a supply system into changing its behaviour. A modern parallel notes that expensive missiles and a container ship's compartmentation can make merchant targets costly to disable, while sustained naval gunfire may be cheaper. That difference explains the force's operational purpose as much as its ship list does.