Armour works best with compartmentation

Which is better: all-or-nothing armour or compartmentalising a ship?

Use both: protect the vital spaces with armour and divide the ship effectively so damage does not spread unchecked.

The preferred approach protects magazines and machinery while retaining serious internal compartmentation. The D-class cruiser arrangement is an example of a design that protects key areas without pretending every part of a ship can be equally armoured. This turns an abstract armour debate into a practical damage-control question.