The minor races do not appear to follow the same production algorythms as the player and (allegedly) the major race computers do. Try this. Start new games until you get one where there is a minor race very close to your homeworld, so you can watch them grow from the very beginning (when they have like 100 pop.). Build a fighter or a corvette or something and get ready to blow up their ships. Wait until they build their first military ship. Blow it up. The next turn, they will have another. Blow that up. The next turn, they will have another. Blow it up. This will continue until the point where it becomes very apparent that the planet cannot possibly have the resources necessary to do it. Yet mysteriously, if you STOP blowing them up, they will not accumulate... they stop building them. It's like they want to have one defensive ship there at any given time, and get it for free.
-Drake
~SDC~