Instead of arguing over whether it's specialization or not, why not discus about whether the level of specialization is really what we hoped for and what was intended?
Spamming 2.5 default districts in every city isn't exactly what I was hoping for, that's for sure.
How would I fix it?
- Fewer districts per city
- Change all districts to synergize more with adjacency of different terrains, etc.
- Instead of scaling districts by technology, make districts become much more expensive for each district of the same type you already have
- Rebalance production so a normal city can construct stuff in a reasonable timeframe, while cities with production-focus can maintain infrastructure + have the capacity to produce armies/wonders in a reasonable timeframe
I strongly feel like there's really a current "production mismatch" because most of the players who think that they're godly at Civ just have no idea how to eke hammers out of the game. I've had no issues making new districts in new cities. The trade routes help a lot. It pays to have a great trade network, and that include both Commercial Hubs and Harbors - having lots of these helps in setting up new cities, or helping out cities that don't have much production in the tiles.
The mechanics inter-relate. Cities that can make both a Commercial Hub and a Harbor are invaluable for powering the trade network, because they give you two trade routes per city. That's important. But equally important is having a few cities that have Industrial Zones and Mines - things that appear to boost the trade output of internal networks. That way, a new city can have equal production and lots of growth to a central production hub while setting up its districts, and then you can redirect the routes elsewhere once the Districts are set up.
There is no "normal" in Civ. There have always been production poor sites - in Civ IV, we'd just buy the buildings of cities that produce gold and food, but we can't settle those early until we get the techs necessary to boost the purchase abilities. In Civ V, if a city is in a production rich area, all it needs is growth and Builders, and it can set out making its own Districts without any issue. If it's in a production poor area, it will probably do well on the food on its own, but need connections to your industry base to make its Districts.
The Districts already benefit from a LOT of adjacencies. Just in my last Sumeria game, I had two cities where both Industrial Zones had the maximum +6 adjacencies - both were smack-dab in the middle of mines and quarries all around. With Craftsmen Policy, they both had a base production of +12 just from the IZ adjacencies. Those cities made all the units. The more central and larger city also had an IZ, but that was purely because it was in the center and would project to something like 6 cities. That's a good site, but I built the District only shortly before Industrialization. There was just no point to building it before - no Adjacencies. In fact, the Entertainment Complex went up first because that projects Amenities before the Industrial Era.
So, here we have a situation in which two of my best producers had Industrial Zones and Encampments, and the central City had Entertainment Complex, Commerical Hub, and Theater District. That's kind of specialized, ain't it? Of course, my capital had Campus, Harbor, Commercial Hub, and my second city had Harbor, Commercial Hub, Holy Site. The Capital and Second powered the trade network early, and then the Industry Cities became targets for hammer-rich routes.