Courageous had the guns, but Renown was the ship Britain needed

How would a Courageous-class large light cruiser fare against a Deutschland-class armoured ship?

Four 15-inch guns give Courageous a severe hitting-power advantage over six 11-inch guns, but three additional improved Renown-class battlecruisers would have been more useful to Britain.

Courageous brings battleship-calibre weapons to the encounter, so her individual shells would be far more dangerous than Deutschland's 11-inch fire. That does not make her a balanced or desirable design. Replacing the three large light cruisers with improved Renowns would produce five ships in the family alongside Hood. Such a force would also raise the British capital-ship tonnage demanded at treaty talks, showing how a better wartime design choice carries a later diplomatic cost.