You can get CoL and preserve the Astro bulb by avoiding Meditation, but whether you should do so is another question... It's unlikely to be useful with a CRE leader when you have cheap libraries and can easily reach ocean seafood.
I'm curious about the situations where you'd want the Great Library in isolation, even with marble. It just seems like a lot of techs to make it work if you didn't need them otherwise.
Great Lighthouse and Mids are the best wonders in isolation by a large margin. Colossus is bad because Astro obsoletes it. If you are IND with cheap forges it is a decent failgold option.
I'm curious about the situations where you'd want the Great Library in isolation, even with marble. It just seems like a lot of techs to make it work if you didn't need them otherwise.
Great Lighthouse and Mids are the best wonders in isolation by a large margin. Colossus is bad because Astro obsoletes it. If you are IND with cheap forges it is a decent failgold option.