Yi Sun-sin as fleet builder rather than a Korean Nelson

Yi Sun-sin and Nelson should not be flattened into interchangeable heroic admirals. Nelson operated forces across a geostrategic theater, whereas Yi's strength lay in building and training a fleet for a concentrated regional campaign. Yi had already succeeded against Jurchen raiders when General Yi Il falsely accused him of desertion, only for Yi Il to fail later against Japan at Sangju. After imprisonment, loss of rank, enlisted service, rehabilitation, a training command, and work as a military magistrate, Yi took command of the Left Jeolla Naval District and spent more than a year improving infrastructure, ships, training, and readiness before the invasion. His scholarly and military family background gave him the ability to research older designs, which may help explain the recovery of turtle-ship ideas.