We (kcd and Indiansmoke) have focused their testing on fast CS with Oracle.
What are our other options?
We want to build the Oracle because we think the fastest team will also do so. How much REX are we missing with this path?
What if we built it sooner, put it N as a blocking city and took Code of Laws? The culture of the Oracle and Confu Holy City might be enough to block Zara from expanding west.
How many cities could we have at t100?
It looks like we have enough land to our west. And the CS sling is worth letting ZY get a city to our north.
Do we need to consider Other Options? Or did we already make the decision (strategy) and are just optimizing the implementation (tactics)?
No decision has been made. "We" should probably probably test a real rapid expansion to compare. "We" is a funny word, because whenever my wife uses it to describe something that "we need to be do", she actually means "you".
The main unpredictabiilty with REX testing is that it will end up using tiles outside the "known" area, and the neighborhood has different actors. What should be the target number of cities by turn 100? We can surely acheive a LOT of cities, but our economy will not be able to handle it for very long, I think. Good to test though, because after we play 3 turns we might find out our CS-sling plan is unworkable anyhow.
Note... getting Confu would allow conversion of ZY and common religion +diplo. But..Maybe we should just start planning for him to be an enemy, given his proximity. Anyhow, it would be VERY unlikely we fail to get Confu on our way to CS-sling. In fact, the ONLY way I've ever been beaten to CoL while going for a sling is if someone builds the Oracle VERY early (say 2200BC) and takes CoL. That happens and we are hurt... but if it happens to everyone due to map-maker manipulation, it hurts everyone the same (except 5th element who is trying to give Classical_Hero a golden opportunity to say "I told you so" at the end of this).
I think its not too late to go to a culture-game if we wanted. I still think diplo game is faster, but diplo game relies more on the AI and the map than culture game does. So we should be open to throwing out our strategy if it looks wrong later.
As for the CS-sling, some comments:
Pro: Once in Bur with the cottaged capitol (and silver), we can sustain a much higher REX rate, and by 1AD have a much larger empire than otherwise... unless of course we get boxed in.
Pro: Diplo win requires good relations, which means giving in to demands for techs and other stuff, gifting techs and other stuff... etc. You get the picture... it requires a substantial and comfortable tech lead which we get by tech trading and by beating AI to every desirable trade-bait tech.
Con: Getting city #3 settled is a lot slower. Getting city#4 settled is a little slower, too.
Pro: I'd guess we can get 5 cities about as fast with the sling as without it, but in a much better economic situation.
So the question becomes: what do you feel about our prospects of getting a decent-sized empire (6 cities minimum, 7-9 good, for diplo voting more is better) just by settling? Or rather...is there enough unoccupied land that we can safely put off our expansion until after the sling? I don't know, but in my experience this usually isn't a problem on Emperor level, unless playing against more than the standard number of opponents for the map. In the worst case, we can always expand by "other means" (stop thinking beyond the sword, and start thinking about the axe

). I think by the time we know whether the REX is better than the CS-sling or not, we will be able to better assess the risks/benefits of using one of our 2 free DOW's.
BTW: the sooner our borders start inhibitting ZY's expansion, the sooner he's going to get p-o'd at us for that. If we want him to start a war with us, no problem. If we don't, then we should be careful. Closest neighbors usually make for hard targets to get their votes, so not sure whether converting him to confu is wise or not.