What did the Renown, Centurion, and Swiftsure types teach the Royal Navy besides lessons about the 10-inch gun?
Short answerThey offered wider operational lessons, with Renown linked to the development of the battlecruiser idea.
NotesThe reply resists reducing the ships' value to their gun calibre. Renown is described as one of the foundations of the later battlecruiser concept. Centurion and Swiftsure are credited with useful operational capabilities. Those capabilities are mentioned without a detailed comparison of the classes.