First of all, this is the relevant part of the GS bulb list. For simplicity I'm discarding bulbing with GEs here, I think they're too difficult to produce anyway, especially more than 1.
Mathematics
Alphabet (BTS)
Philosophy
Paper
Aesthetics (BTS)
Iron Working
Metal Casting
Engineering
Machinery
In all cases we'll have to self-tech (or trade
) math, alpha, aesthetics and IW before we can do anything on the path to engineering. If we get these out of the way and we Oracle MC, then we just need 2 GSs for engineering and machinery.
On the other hand, if we Oracle CoL, we open up philo and hence we'd need 4 GSs to do the same, supposing we bulb MC rather than teching it.
However, with caste and pacifism we can crank out GSs much faster while we don't necessarily need libraries to hire them.
Turns it takes to produce great people. Number of turns is based on GPP required for subsequent GPs (100, 300, 500, 700...) divided by GP generation per turn.
With no caste, assuming 2 hired specs being PHI:
1st: 9
2nd: 25
3rd: 42
4th: 58
So if 1 city should produce them all, the 3rd one comes in 9+25+42=76 turns. But of course with 2 or more cities with a library those turns aren't cumulative.
Turns it takes to produce great people with caste, assuming 4 hired specs being PHI and supposing pacifism from the 2nd GS onward.
1st: 5
2nd: 9
3rd: 14
4th: 19
First point: assuming that in either case we have 2 cities producing great people. Note in the MC scenario we'll have to whip 2 libraries and regrow to 4. However, in the CoL scenario we need 2 cities of size 6. I think roughly that takes equal amount of time. In that case in MC scenario the 2nd GS is popped at T+25, while in CoL scenario the 4th one comes at T+28. Timing wise that's not a significant difference.
Second point I want to make is in either case: should we even try to actively seek a GPr as first great person (although IF we want one THEN it should be the 1st one imo, later it's too difficult)? In the MC scenario that means the 2nd GS (3rd GP in total) would take 42 turns to produce. But obviously also in the CoL scenario it delays the road to engineering, although the 5th one with caste/pac comes a lot earlier than the 3rd with MC. Important to note we can NOT bulb theo anyway until we bulbed engineering, as otherwise we open up paper. So maybe we should just self-tech theo, while producing all the great people. First math/alpha/aesth/IW then mono and theo. How long would that take?
Third point/consideration: Pyramids in the cap costs 500 hammers. 16 base hammers at size 5 with stone bonus means it can be built in 500/2/16=16 turns, with some chops in about 12. Representation gives obviously an enormous boost to our tech, especially in case of caste. Assuming T63 Oracle, T71 SoD ready then T84 (give or take) representation.
Fourth point: careful with the whip when constructing the SoD. In either scenario it can be detrimental to GP generation. At least the envisioned GP producing cities should be whipped lightly, if at all. What interests us is having as large as possible cities. Possibly that means we should be farming a bit.
Possible city configuration "shortly" after T71 for caste:
Stone Hill: Size 5, 3 GH mines, bronze, farm. Stagnated, building mids.
Marble: Size 4/5, growing rapidly on corn+FP. At 4 it could work just corn + 3 sci specs and give back FP to cap.
PearlySwine: Size 6, working pig, gem, farm + 3 sci specs.
GoldenFleece: Size 5/6, 3 or 4 sci specs.
For 3 spec GP seneration we have something like this:
1st: 6
2nd: 11
3rd: 19
4th: 26
That would mean engineering bulb around T71+6+26=T103, assuming 3 cities producing great people. Note that some Jap city might help too. If we somehow manage to create the SoD without the whip we might actually switch to caste earlier and hire some specs in for instance Pearly Swine and be a bit earlier to the party.
IIRC Ororo talked about 400BC as an objective for engineering. T100=375BC I see in SGOTM graphs, so T103 wouldn't be too far off.
One unknown is the general tech rate meanwhile. If it really is rather good with caste and mids, we might actually just self-tech MC too. In that case we only need 3 GSs for engineering, speeding things up more.
We should test things out.