Army Challenge Rating for diminuitive army

[LucyG92]

I'm trying to model a group of about 10-15 people as an army to simplify things like resource usage, using the rules in Ultimate Campaign.

The ACR for a diminutive army (10 people) is the CR of an individual creature -6. So if they're typically around level 2, that would make the ACR -4. It says if the ACR would be lower than 1/8th, it isn't an army - I'm not sure how to compare -4 to 1/8th, basically. :/

[Dave Justus]

-4 is less than 1/8.