It shuffles (almost) the entire cast of Stardew Valley, assigning new roles to each character at random.
Age, gender, and datability are maintained by default, and you can place any character on the forbidden list to stop them from being swapped (George is on this list by default).
Under the hood, NPCs are still the original characters, their names and graphics are just swapped. Names in the dialogue and other strings are also swapped (mostly). It really shouldn't break much beyond animations that don't exist on swapped characters. It might, though.
Technical
Requires SMAPI, uses Harmony.
Compatible with Mod Updater for automatic updates.
Code is at https://github.com/aedenthorn/StardewValleyMods.
If you want to complain or ask for help or help me test my mods, you can visit my Discord server.
A list of all my mods for Stardew Valley is available at https://www.nexusmods.com/stardewvalley/articles/895.