@strategyonly @Thunderbrd @Dancing Hoskuld @JosEPh_II and others:
Do you choose single city, where you build all buildings or at least all resource producers no matter what?
I think this is good strategy for any handicap:
You make sure, that you always have manufactured resources, and you prevent obsoletions from surprising you.
Rest of cities are just minding their business.
Pollution problems (resource producers most likely add pollution) in single city aren't that bad especially if that city builds all buildings, since properties are "diluted" by buildings.
I think you should buildings, that are required for other buildings in all cities too.