Why the Fletcher fit US Pacific doctrine

Was the Fletcher class the best choice because it fitted US naval doctrine?

Yes: it suited a US Navy preparing for Pacific fleet warfare, where its destroyers were expected to support massed operations.

Ship design starts with the war a navy expects to fight. For the US Navy, that meant Pacific operations and the possibility of large destroyer actions. An Atlantic war against Britain was a contingency, but not the principal design case, while the Royal Navy's Tribal class already reflected a different need for more gun support among destroyers. The comparison discourages judging either design apart from its intended theatre, fleet structure, and doctrine.