At its core, Better Settlers is a lore friendly mod that adds more than 160 new settlers to the vanilla settler selections (for a total of 190). You can choose to leave them with vanilla equipment and stats, or: It allows you the OPTION to make lore-friendly changes to their equipment, stats, or mortality. Other options include: mod-created equipment and hair (highly recommended), all female settlers, or raiders as settlers. All of these options are randomly generated when the Settler spawns, so no two settlers should be exactly alike.
Better Settlers works extremely well with the Dont Call Me Settler mod, which adds unique names to settlers. I highly recommend it.