Raider's do not a sufficient Navy make. The Confederacy made no serious effort to establish a sufficient size blue water Navy that could do what a Navy is supposed to do and that is secure it's ports and maritime trade routes.
Think it depends on the purpose of the navy. Navy's seem based on one of two philosophy's 1. Sea Control, takes the largest and strongest navies in the world, US today or Britain WW2 and before, or 2. sea denial- where one realizes they cant possibly compete for control, so the purpose of the navy is to limit or deny the others control. raiders and submarines are hallmarks of this philosophy, the U-boat fleets of the 2 world wars, the soviet navy of the cold war, Chinas today, were built on this second philosophy, and its never intended to gain control of the seas, but to simply hinder the larger navy and merchant marine