Riding home from work today, your comment from earlier about having production enhancing buids surround a special tile.  At the time, I was thinking it should be the other way around, with the plaza concept I was pushing.  That's for when you had gardens and workshops.

Now, I get it.  The special production tiles ARE what anchor a city, and give them their uniqueness.  So, a city lucky enough to have fertile ground is going to be the breadbasket city for the nation.  Other cities won't be able to self support past level 2 without some food coming in from somewhere, maybe level 3 late game with advanced farming.  So, it now makes sense to me that you'd have mulitple build production enhancements all around the 2x2 tile of the farm, bumping it up as much as possible, so that other specialty cities, like the mine, or the shard, or the crystal, or the materials cities can get the food they need, while at the same time, other cities can get those goods to the food city.

Got it; looking forward to playing it.