omg I had typed up a response, but then "the server is too busy at the moment" so my post disappeared 
Anyways I got the full game today and started up an emperor game. Stonehenge was completed by the AI at turn 50, which isn't fast, but i think it will be hard to get both it and TGL. I mean we could probably get both built, but it would be very hard to both build the stonehenge AND sling civil service from the great library, since before we can complete TGL we'd need:
Pottery, Calendar, Writing, Animal Husbandry, Trapping, Philosophy.
And by then i'd think that an AI will already have completed the great library. So we'd probably be better off with your GS suggestion. Get stonehenge, then build a library for the two scientist specialists so we can grab CS with our GS, and maybe get mining somewhere in between.
The tech path still works:
Pottery -> Calendar -> Writing -> Mining. Then we could time the pre-req techs for CS to be completed for when our GS pops.
Build in our cap could be something like this:
Scout -> Worker -> Stonehenge -> Library -> Warrior -> Settler

Anyways I got the full game today and started up an emperor game. Stonehenge was completed by the AI at turn 50, which isn't fast, but i think it will be hard to get both it and TGL. I mean we could probably get both built, but it would be very hard to both build the stonehenge AND sling civil service from the great library, since before we can complete TGL we'd need:
Pottery, Calendar, Writing, Animal Husbandry, Trapping, Philosophy.
And by then i'd think that an AI will already have completed the great library. So we'd probably be better off with your GS suggestion. Get stonehenge, then build a library for the two scientist specialists so we can grab CS with our GS, and maybe get mining somewhere in between.
The tech path still works:
Pottery -> Calendar -> Writing -> Mining. Then we could time the pre-req techs for CS to be completed for when our GS pops.
Build in our cap could be something like this:
Scout -> Worker -> Stonehenge -> Library -> Warrior -> Settler