Except that disconnecting a city from recources also disconnects it from luxuries ... leading to either an unhappy city or too many entertainers. Either way not as productive as it could be. And to point was that you *wanted* to avoid the UU-triggered GA, as it would come much too early to be useful when you're playing the Aztecs or Egyptians, for example. That was my thinking in coming up with (or rather, stumbling across) this strategy. The late Middle Ages or early Industrial Age GA is a killer.