For many players, the full version of SoS is overkill. The full framework allows for different sizes, types (erect vs. flaccid), and even racial variations that are distributed via scripts to NPCs throughout the world. However, if your goal is simply to: Have a realistic body for your own character.
Generally, body mods should be placed relatively high in your load order, but below any general mesh or texture overhauls to ensure they aren't overwritten. Integration with Other Mods schlongs of skyrim light se
Because it doesn't try to "manage" every NPC via a global script, it is often easier to make it play nice with other armor and body mods. For many players, the full version of SoS is overkill