It depends on how much we sacrifice for an early TGL, e.g. a quick test shows that a T57 TGL is possible with just 1-chop (@20H) and three whips (Settler/Worker/Axe).
I have not thought about whipping 3 units to gain OF to TGL. The way hurts capital too much. We gain TGL by a few turns, but then lose the yield from extra citizens for way longer time. 2 more scientists/other tiles in 10 turns plus 1 more scientist in another 10 turns obvious beat the yield of TGL of 5 turns earlier. Moreover, I doubt the usefulness of the worker since we are expecting free workers soon.
These are good points, but most of them are applicable to an Aesthetics ----> Literature ----> Currency tech route as well. The issue is a matter of order, i.e. will we choose to build Wealth between T47 and T62 because we have gone to Currency before Literature, or will we own Asoka's second city by T62, or do we need to bring Tokugawa to Pleased before T62?
Those don't apply to Literature 1st approach since you don't have Currency in ~15 turns period, hence you can't gain cash from trade to speedup research.
I'm not sure about #1? For #2, yes I agree about Polytheism. For #3,
yes.
We could please an new AI with merely 10g, which is possibly required for tech trade. and again we could gain cash from tech trade, like Alpha<->IW.
Currency is more flexible, for sure, but it seems very optimistic to me to expect that TGL will be built by T63 in a Currency ----> Aesthetics ----> Literature route (without Mathematics), and even if TGL is completed very quickly, the National Epic will be delayed in its turn.
If as your test that T62 Literature without cash from AI, then as I told, T60 Literature is not difficult. With 3 workers to prechop forests plus OF, I don't see T63 TGL is a tough call. It does not even need to sacrifice the capital.
Anyway, I don't mind too much. I think we need 3–4 Great Scientists before Lib:
- Academy
- Philosophy?
- Education
- Liberalism
Assuming we have an Academy already, 900GPP only requires 30 turns for a city with 30 GPPs per turn (running two Scientists). Without the NE, it will need 65 turns. If we ignore Philosophy, just 17 turns are needed to generate GS #2 and 3 (with the NE) or 36 (without the NE).
In either case, I think we will have a tougher time researching the intervening techs (Music/Civil Service/Paper/Nationalism etc.) than generating Great People.