Are you building an army of identical Robot Skeletons? A squad of white-painted "Stormtrooper" Sheks? Without presets, every new recruit you spawn via the Recruitable Prisoners mod or the Hub bar would look random. Presets allow you to enforce a uniform aesthetic for your faction.
The character creator in Kenshi is notoriously granular. It allows you to adjust everything from the length of a Shek’s horns to the posture of a malnourished Hive Worker. However, because the game’s "muscle" and "fat" sliders react dynamically to your character's in-game stats (like Strength and Cooking), a preset serves as the .