I really don't understand how you're all waiting until Ancestral Hall to settle cities. That means getting Political Philosophy, building the Government Plaza, *and* building the Ancestral Hall. That's, what, turn 60-70? And how many cities have you settled by then? It should be probably 6-7!
Two or three cities (besides the capital) is what you're aiming for. Each of those should have a monument. Your prioritize culture and military over science and build the Gov Plaza as soon as it unlocks - you want it build before Political Philosophy.
Not sure if it would work on Deity since I never play on difficulties higher than immortal but there's no risk on King, and very little risk on Emperor if you use Agoge to quickly build 3 Warriors and 3 Slingers after your first Settler.
Generally the build order I use is this (King/Emperor difficulty, huge or large Seven Seas / Pangaea map, default number of AIs)
1. Scout =>2. Monument => 3./4. Settler / Builder => 5. Warrior => 6. Warrior => 7. Slinger => 8. Slinger => 9. Warrior => 10. Slinger / Archer => 11. Gov Plaza
by step #6 you should have Agoge and Urban Planning as your policy cards, which you should retain until you reach your tier 1 government. I don't bother with God King - the most "consistent" way to guarantee the free settler is to meet a religious city state or pop a relic from a goodie hut. Just go Urban Planning and grab a scout instead.
You need the scout to fish for the Political Philosophy Inspiration (and it also helps you get in some extra yield tricle from City State First meeting bonuses, particularly Religious and Cultural ones), and the builder for the Craftsmanship Inspiration.
if I dont have Political Philosophy by the time I finish the gov Plaza, I usually go for a Wonder (Temple of Artemis is usually worth it) or a second settler, but I mean, that depends on what I need the most. The order isn't fixed, it's fluid and should be adapted to whatever needs you possess.
Policy Cards: Agoge, Urban Planning (Chiefdom) => Conscription, Urban Planning, Colonization, Charismatic Leader (Oligarchy or Classical Republic)
in the extra cities I settle i usually go Warrior => Monument => Builder => Archer. (usually a trader before the archer in my second city for the Currency Eureka and a road to the capital). Once Currency is unlocked I build Ancient Walls followed by the commerce district, the market/lighthouse and a trader. .
I also combo this with Magnus + Provision and that promotion that gives +2 Food to internal trade routes. With a CH/Harbour and a Campus, that provides a solid +5/+2 internal trade route to help the new cities grow faster after you've built the commercial district of choice.
This strategy works the best with Rome because of the Free monument they get, Gorgo because of the easy culture from kills and Russia/Korea/Japan because they get half-price districts that help you get the State Workforce inspiration. Any civ with a high production start can pull it off easily though.