Small Station Expansion Update

I don't know if this has been brought up in the past. I tried searching for it but no results. Is with the small fire station, is allowing to have 1 expansion upgrade under the small fire station. The reason for this, is I don't need 40 slots, and most realistic fire station don't have more than 3 units in large urban cities in the US. If you need more than more one expansion upgrade, then yeah make it where we have to upgrade to the full fire station.