I like the idea of gambling for CS

- so I played around with CP's suggestion of a marble city
I redid the math and yes 17 turns it'll take to bring marble on line and then 2-3 turns to chop/build Oracle with prechopped forests in Moscow, but we can't research CoL in 19 turns with Masonry. With no trading it will probably take 22-24 turns.
Marble city as city4
If we build city3 as planned and after that Marble city on the ruins N of the rice we can have marble on line in 19-20 turns and Oracle 2 turns later with prechops.
This means getting the next settler out of Moscow in 10 turns and then 5 turns of traveling and 4 turns to build the quarry with two workers.
Pros: The two cities will be productive from the start. City3 can produce a worker in 13-15 turns with some help from the worker out of St. Pete.
The two workers will have time to scrub the rice (or the deer) before scrubbing the marble and they don't need to wait for the border to pop before they can build the quarry, so city4 will grow from the start, it'll be connected by river to city3 and our capital. Long term N of rice might be better than 2S of marble.
Cons: City4 will not be on the coast.
If we go for CS-sling with marble it will be delayed 3 turns (masonry) no matter what!!

There are other nice wonders that need marble, and both city sites should be able to whip some workers.

Of course we could rex faster if we don't go for marble now.