It says something about how a force expects to deploy regularly. What I mean is that the smallest interchangeable unit matters in organization. Yes, the actual tactical level varies a lot – if you have 8 fighters then it might be a Flight, but 800 you could and would arrange many different ways.
First, I’m going to distinguish between Wing or Group as an organizational level and the colloquial wing or group used to describe a ship or command’s combined fighter assets.