How Britain might answer completed Francesco Caracciolos

If the Regia Marina completed the Francesco Caracciolo class, would the Royal Navy need faster capital ships?

Yes. Britain would generally have to respond with faster capital ships.

Speed matters here as an operational requirement rather than a cosmetic performance figure. If the Regia Marina received the Francesco Caracciolos, Britain could not rely indefinitely on a slower capital-ship force. The Royal Navy would therefore need faster ships in general. The exchange establishes the strategic premise for the treaty-limited British design exercise that follows without yet fixing its armament or protection.