Cities predated agriculture. Look up Göbekli Tepe -- this is a common misconception and worth correcting yourself on.
No evidence of cultivation, but extensive evidence of cereal / grain processing - surrounded as it was by abundant wild grasses and steppes.
The argument made by some is that processing grain (winnowing, grinding with stone, ovens, etc) induces a fixed "city" life via the not especially portable capital investment.
Certainly an avenue of thought worth investing time in.