Having a look at the improvements this shows wrong priorities. You need no courthouse in the capital. You not really need barracks. You need no marketplace before quite late. You probably should not prioritize a temple if there are wonders AI may snatch from you.
There is nothing in the 20K-town screenie to show Aiken_Drummurabi's build-priorities; the list of town-improvements reflects their order
in the .biq, not the order they were built. And that screenie
is from the late game: the date is 1864 AD, and the 20K-town obviously already has a Factory+PowerPlant, so Industrialization must be known (and presumably Universal Suffrage has already been built?).
So with the exception of the Courthouse (which is never needed in the capital), I'm not sure that statement is really justifiable?
For a 20K game, a Temple is definitely a worthwhile build
at some point. And the Babs know CBurial from game-start, and get Temples for 30s, so it represents a cheap rush-job which can be completed at the player's discretion, and relatively early — though better after the first Settler and Colossus, of course! — for the multiplied Culture after 1000 years.
I'd also have thought that a Market would be a good build for the Lux-Happies, to ensure that my 20K town stays happy (and/or enjoys WLTD as often as possible), especially once it hits metro-size after Shakespeare'sT has been built.
And while a Barracks should not be an early priority for 20K, the Crusaders show that KT was built, so a Barracks to boost them to vet-status is certainly desirable.
(If I'm ever able to build SoZ, then I will likely not be hand-building much additional military — so a Barracks would usually be my very next [rush-]build in the SoZ-town, to ensure that all my ACavs start as vets.)
What did strike me more about those screenies was that there are still multiple obsolete units in play (Spearmen in landlocked towns?
Why?), and a large stack of idle Workers in the 20K-town. So I do wonder a little what the Babylonian military budget looks like...?
I mean, income is obviously already quite healthy, but some of those Workers could have been joined to
at least the 20K-town, to bring it to Pop20 -- and/or added to all the other coastal cities to bring them all to Pop12 -- for
even more commerce per turn.
So it's possible/likely that research could have happened faster than it apparently did; the current research project is still only Atomic Theory (in 1864) — and ToE will 'unfortunately' finish before AT, so one of those 2 free-techs will be wasted (unless the remaining beakers can be bought from someone else?).