Your options for small numbers of people are:
- One person, less powerful: -5 points
- One person, equal in power or 3-5, less powerful: -10 points
- One person, more powerful or 6-20, less powerful: -20 points
It looks to me that the third category has space to become something like:
- One person, more powerful or 2-3, equal in power or 6-20, less powerful: -20 points
It would be the same price as two separate Enemies, just bundled into a convenient unit to save space on the character sheet.