How powerful would a combined Grand Fleet and British Pacific Fleet be?
Short answerWith the Grand Fleet upgraded for 1945 combined operations, it could be the era's most powerful fleet and make an invasion of Japan more feasible.
NotesThe comparison depends on upgrading the older Grand Fleet for combined operations rather than merely adding hull counts. Its ships would need the technical and logistical standards of the British Pacific Fleet before the two forces could operate as one. With that integration, the combined fleet could become the most powerful concentration of naval force in its period. Its mass could also make an invasion of Japan more viable than it was with the historical fleet alone.