The Royal Navy's overlapping secondary and destroyer guns

What did the Royal Navy get wrong at an institutional level during World War II?

The first example is failure to settle on a more consistent secondary and destroyer gun system, with many calibres and marks multiplying support demands.

The first institutional criticism is repeated pursuit of a new secondary or destroyer gun whenever another design looked promising. Each change added organizational, logistical, and training demands. Large purchases made individual systems look supportable, but did not remove the burden of operating many systems together. The wide spread of calibres could include several marks of each, with further designs still under development. The criticism favors improving a selected system over repeatedly adding another distinct one.