We can't. Let me explain why.

As factions are currently coded, they are a number. That's it. It is up to the
coder to set the faction values to whatever they want, then code their own
monsters/rooms/items to react to those numbers however they want. The
positive/negative or size means absolutely nothing out of context. If I told
you your Bat Cit*cough cough* your _Arelium_ faction was 499, that would mean
nothing to you. For all the game knows, that means you killed 499 civilians.
The coder assigns all changes to factions, as well as any max/mins that exist,
completely arbitrarily and the system you're describing can't take that into
account.

Shinarae Lluminus