Imo, government competency is probably the biggest determining factor. From experience during my past iterations in Orbis, micros are generally bad if they have inactive leaders, suck at the game, or don't know how to position themselves diplomatically. So I'd judge competence mostly on their leaders' activity, game knowledge, and how they interact with other alliances. The second is how quickly they can grow out of micro status, since that really is the goal (or should be) of all micros.