The first point to make about British naval rearmament in the 1930s is that the Royal Navy was preparing not for war, but to deter war, at least until after March 1939.
Grove, Eric J.
"A War Fleet Built for Peace: British Naval Rearmament in the 1930s and the Dilemma of Deterrence versus Defence,"
Naval War College Review: Vol. 44
, Article 7.
Available at: https://digital-commons.usnwc.edu/nwc-review/vol44/iss2/7