King Mosiah continued as king, but also appears to set the government of judges in motion. It is speculation, but it would have been prudent to institute the reign of judges while he was yet king, so that any issues could be brought to him as the king and recognized leader. When he sorted out the issues, they could be claimed to come through his divine authority.
The remembered legacy was the one that Benjamin had desired. Mosiah was remembered for not delighting in the shedding of blood and the establishment of peace. As with Benjamin, he took credit for things he did not do, such as not exacting riches from them. Mosiah, as did his father, represented the best of Nephite governing ideals.