The Kormoran was a raider. an reconfigured merchantman.He(German ships were masculine)was armed with four 5.9 inch guns an assortment of lesser weapons and several torpedo tubes. She also carried a scout plane. Her weapons were hidden under plywood and canvas cabin structures and were revealed when attacking. It is believed that HMAS Sydney was surprised by Kormoran.Normally a ship with the speed and weaponry of Sydney, 8 six inch guns and 30+ knot speed, to the Kormoran's 19, would have had little trouble dispatching the raider.
One thing is true, the Krauts had excellent naval gunnery. This was true in 1916 at Jutland, in 39 when Graf Spee brutalized HMS Exeter, and in May 41 when Bismarck destroyed HMS Hood.