So, I've been thinking some on this...
Lio-X had the lover-cop power. While we got on their case for this, it DOES seem strange to have that power included if the only lovers included were Lio-Xeiron and Sudgy-unknown. Therefore, we can make the same assumption that Lio-X made, that there's 3 sets of lovers.
With this knowledge, lover-cop is pretty powerful. A positive result nails scum.
If there weren't scum in lover pairs, would there be a lover-cop included? Seems to not have all that much utility.
What we know: Nkirbit claimed non-lover. Nkirbit was the night kill. Sudgy doesn't know who his partner is.
What is there are two scum, and they're BOTH one-half of an unknown-lover pair. Sudgy is one scum, doesn't know who his lover is. Someone else is another scum, and also doesn't know who their lover is.
This would completely explain the Nkirbit kill. He's the one person who came out and claimed non-lover. Scum would be wary of possibly targetting their partners -- out of the remaining players (Mail-mi, Eevee, Raerae, EFHW, myself (one of these would be scum)), they have a 50% chance of hitting a scum partner if they aim blindly. But by killing (or poisoning) nkirbit, they have a 0% chance of hitting their scum partner.
This is solely set-up speculation, and not based off of reads of people, but this would make sense, and go along with the Nkirbit night kill. Also makes sense in terms of game balance, and the game not ending too quickly either way.
Setup would be:
Lio-Xeiron (lovers, town)
Sudgy (scum)-unknown (town)
unknown (scum) - unknown (town)
Nkirbit (town)
Unknown (town)
Unknown (town)
Probably not true, of course. One problem is that it becomes far too easy for the town part of the scum-town lover pairs to claim to sacrifice themselves. Perhaps one of the solo unknowns would also be scum in that case?