I love the villagers and guards sprues a lot, but what could be really cool is a sprue like them but designed for RPG miniatures, like dnd characters.
A lot of sprues have pieces that could work but they lack some of the diversity players love, both in gender (more female kits would be amazing) and insmall customisation bits! I think it would be best to keep it all human with maybe some heads that are a little less human, like maybe orc tusks, demon horns, etc on a couple heads.
Gear could focus on a mix of classic weapons (swords, axes, bows, etc), magic items (staves, spell books, magic effects etc). and accessories like bags, cloaks, maybe some smaller stuff like the necklace in the villagers set.
Having it all designed to mesh well with the villagers (normal and elves/dwarves) and guards would make it even more versatile upping the value.
I'd avoid any sceneray/basing stuff that isn't super generic (like the bucket and geese in other sets) as with my copy of the elf and dwarf villagers sprue the multiple anvils feel like a bit of a waste.
TLDR: Male and female fantasy adventurers with a wide variety of heads and accessories to allow for customisation of heroes, leader, and RPG style player characters, effectively a hero building sprue instead of an army builder.