Did the Apostle Paul Target Strategic Cities in His Mission Work?

So much for the "cities of influence" idea that some church planters model off Paul: Did the Apostle Paul Target Strategic Cities in His Mission Work? – Kevin DeYoung:

"(1) Most Greek cities were organized as an independent polis governing their own affairs. The “radiation” effect from one city to the next would have been limited by this independence, not to mention the natural barriers (mountains, rivers, seas) that often delimited cities."