Excelsi
Chieftain
Forgive the newbie questions, but what's the benefit of tightly packed cities? Don't they just lock out workable tiles? I'm guessing it's to do with running lots of specialists but why? To keep maintenance or travel down?
Most cities don't reach 20 population until the late game, and even then they're plagued by unhappiness and unhealthiness to the point that they can't work 20, barely managing 15-17.
Thus, it's more efficient to pack cities tighter together in the early game; it maximizes the amount of tiles used as well as the number of cities. More cities translates into more commerce, more research, more production, and eventually a much better position for three legendary cities or spaceship part production or construction and training of a massive army.
These are offset by several advantages:
1. You work more tiles sooner (normally).
2. You get more per cities rewards (EP producing buildings, AP/UoS/SM buildings, trade routes, corporations).
3. Lower pops mean fewer cap issues (health in particular, but also happy). This can also allow you to use the much higher potential happy cap to whip/draft down for a quick shot of instant mass production.
4. It becomes much easier to hold key tiles against aggressive culture as you have more cities putting in their base culture (+20 for the rings) on an individual tile.