Some thoughts about realigning module requirements:
Logically: Shield generators require energy sources. In space the source has to be self contained and hence will have a fixed output. More shield generators would therefore need more energy modules. The same line of reasoning could be true for city shields and hence the two should match ... but ... cities could be allowed to access other energy sources, for example geothermal, which is potentially unlimited so one energy module might be sufficient for a city; in which case space stations and cities can be different in terms of energy module needs if desired
Gameplay: Since a city's loyalty is determined by the orbiting station faction what reason (other than the joy of vandalism) would there be to attack a city? Capturing it is effectively impossible whilst the station's Command Module survives and if you destroy the space station Command Module then the city either goes 'free port', ie IND or swaps to your faction's control when you build a new station Command Module. From that point of view, city shields protect from vandals and the occasional bird or 'badly flown ship' strike
The only non-hostile city module destruction I can envisage is if someone wants to extend the city seamlessly and might want to lose a few peripheral modules or reposition some modules or relocate the city to somewhere nearby.
A related question. If I build more than one city on a planet, what determines which is the primary city - in fact do primary cities exist any more or are they all born equal?
There are so many more complicated things to get your head around in this game that I wonder if the difference between cities and station energy module needs really would cause confusion if it was made clear in the instructions?
