Personally I haven't an issue with the smaller "complete" units for BA as it is still within the letter of the law regarding the Army Challenge that you end up with a completed army at the end of it.
However, feel free to enter several of these a month if you wish
For example next month: Officer plus two guys, Medic plus two guys, Artillery observer plus two guys.
It's still only nine figures, but it's three "units". I'd still only count that as a single entry for the Challenge, but it would benefit your painted collection no end which is of course the purpose of the Challenge in the first place