I really didn't think there was anything wrong with leaving the NONE (atmos-type) out of the equation and only using atmospheres. If I understand the dilemma a bit, I'd say quit worrying about balancing the NONE types and generate ONLY NONE atmos-type moons while telling any players considering NONE atmos-type to forget it. In this version, the moons only become useful as a single-fac place to post a refuel station, SY, or a single training facility (which helps out stopping the 2-moon/planet NONE atmos-types building both training facilities on all three places).
Just a thought. (grin) I'm reminded of the times I took it upon myself to write a program to do a function people wanted and when I took the time to do it, I got a lot of, "Can you add this?" or "Change this to..."
(poor Geo)