If we move the #1 settler straight north, build a road, and simultaneously move the #2 settler to the 3/4 special SSC spot, they will both arrive at their respective founding spots simultaneously. This means that in exatly 4 turns, we will have 2 cities producing 3 beakers, and science will be pretty quick. The SSC/Capital must be foounded firs, so as not to waste that very vulnerable trade. Two whales gives two more arrows, and if it is founded 2nd, those will likely be lost to corruption, and slow progress to Monarchy (plus gold buildup) significantly.
The power city will be up north. It is going to produce over 30 shields before RR, and it wil also easily hit 120 trade. I think it is going to hit close to 150 trade at times. The southern capital option will not be as powerful, naturally (without the whales). It will be a minimum of size 33 city, and likely a size 35... and the city will be able to generate over 1500 science beakers by itself (in a democracy with the proper attention).
But the critical years are until Flight. With republic, colossus, and KRC, the SSC can almost single-handedly defeat all comers. But even Republic + Courthouse + Roads cannot save the waste (shields) and corruption (arrows) if it's gagantuan output is hobbled by not having the Palace.
The other option is to found the capital in the original spot 3 turns earlier, and later build a 100-shield (half a wonder) palace at the 3/4 SSC spot. I do not like that option, but it is something for the citizens to consider.
All we are losing is 6 food and 6 shields by building the capital at the SSC (3 turns of production). No net science is lost because of the extra arrow output of the SSC vc. the original spot.
The point about the "lost" squares of production is valid.... but those squares will not be lost, as a city will be founded that will spend it's life using the tiles between the 1st and 2nd cities. That middle city will likely be 2 (or maybe 3) squares north of the southern city (the #2 city) site. The east must be kept clear (e.g., not crowded by placing the #2 city further east), as it can right now even support #4 and probably #5 cities. If the #2 city (the #1 settler) founds to the east of the road, this area will be heavily impinged upon. The #1 settler has an ideal site (the original NW site) for shield production & growth & spawing new cities (e.g., settlers) rapidly. It will likely be the mother of all cities

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