it's particularly interesting to me the low number of cities... i'm all about efficiency and would love to move away from the 12+ cities ifound myself tangled up currently
could you comment on the number of territories and districts?
From memory, 4-5 territories attached for the cap, 3-4 for the second city, 2-3 for the others - so nothing very special or outrageous. I did capture a lot of territories early with the-50% outpost civic - I usually try to "wall" off the AI by forward outposting the territories on his border, then backfilling.
I built ALL the ED in ALL the cities as far as I could immediately upon entering a new age (some cities were obviously taken "too late" to get pyramids up for example). I believe i missed 2-3 of the Joseon districts because I wanted to go French and didn't want to wait for the last straggler city. In terms of "other" districts, i built a few makers quarters when it made sense to do so, but relied mostly on EDs and smart infrastructure picks like the aforementioned stables, forges, irrigation, water-wheel industry thing... I did start building science districts just after building the Mauryan stupas, as that coincided pretty well with +5 science on science district and didn't really stop building them until I built the french ED and after that went full collective minds (which surely prevented me from going modern, as I did not get enough builder stars). I got the "middle" era" science infrastructure, but not the "early modern" stuff, as per the guide probably the payback-time would have been too long.
Believe when I started going full collective minds, the science output was ~20K-25K(?), which was plenty to get the final techs I needed. Because I had a lot of territories, I did not need to go anywhere to secure oil, aluminium or uranium. I also got all the science tenets for all the religious tiers. Not sure how impactful this is, but suspect actually a lot as it adds up during the game.
I think the reason the strategy also works with less cities than the persian +2 is that the last cities you found/steal/capture will not significantly impact such an early "end date" for the game. But then again, my game was not a turn 76 game, maybe more cities is needed for that. The Mauryan bonuses are also, excluding the obviously great +2 cities, overall better than the Persian ones (IMO). better ED, cheaper territory attachment and a bit more influence. It also allows you to buy-out independent peoples that are hard to reach militarily, as it is cheaper for asthete civs. The actual asthete ability (buy influence on territory) seems like a lot of nonsense though, but correct me if I am wrong.
I am also now just starting a humankind-level game, so I rerolled for a mammoth-heavy start and can confirm that it is possible to get 260 influence by turn 10 as the original game claims, it does takes a bit of save scumming though to correct some risky solo-mammoth plays, must admit that

but we should not be naive and think these crazy fast games are played under "purist" rules like no map knowledge or no reloading early mistakes.