Ranks scaled for a galaxy-spanning navy

The long ladder from lieutenant to Lord High Admiral is a plausible response to a navy controlling enormous areas and fleets. Rear admirals gain administrative experience before higher command, while vice admirals and senior captains have substantial independent or scouting responsibilities. Extra senior ranks for crusades and battlefleet command establish authority when many experienced officers must cooperate. In a service where officers may hold rank for centuries, a temporary higher title can settle precedence that seniority alone would leave dangerously contested.