A submarine torpedo and magazine explosion could destroy many light cruisers, so Armando Diaz's loss alone does not prove that the design was uniquely fragile. Her disappearance in roughly six minutes still raises questions about subdivision and the aggressive effort to save weight. The class was a very fast specialist built around a particular 1930s forecast of Mediterranean combat. Sacrificing some speed could have bought much better protection and room for later improvements, but it would also have changed the doctrine the design was meant to serve.
Chapter · 33:46-35:42
Speed specialization came at a survivability cost
The class made sense as a fast 1930s specialist, although its subdivision, protection, and lack of growth margin limited survivability.