This took my interest, 6:02 is fast for a ff, so I’ll try to replicate it best I can with different civs.
Disclaimer: I’m not the best at impressive strategy crafting or the game in general.
´\ _ (°<°)_ /´
So, tried it for myself with USA.
Using the deck (sending the capitol card last, for faster age up) i managed to get to 3rd on a normal competitive map at [05:25].
Note that i went with the 700f age up (to 2nd age) and New Hampshire (for 3rd age) as the player you showed, that way i got 5 regulars at the age up, with 12 settlers at hand.
I had enough xp for the gatling guns to be sent next and push at the enemy (the 5 regulars to defend them).
Next I tried it with Ottomans.
Had high hopes 4 this 1, but i got to ff at [06:42], there was no way to accelerate the age up, so even if I clicked it at the same time as USA, without the capitol card, I can’t save the time.
Anyway, with the age up i received 4 Delis and had 14 settlers available.
I had enough xp and almost enough gold to send a manchu card, to push with the Delis at the enemy.
(Probably works best if you go for food instead of gold and send Spahi, as well as age up with abus guns to have a more diverse army to push with)
NOT GOING TO TRY AN ASIAN CIV NEXT CAUSE THAT WOULD BE CRAZY HARD
that’s what she said…
Next is Ethiopia, and boy oh boy, I suck at playing this civ.
With mostly crate shipments I aged up to 3rd at [07:42].
Nowhere near of a 3rd age shipment, I aged up with 7 Sudanese Dervish and 13 settlers. In desperation, I sacrificed 2 cows to the gods to go 2nd age quickly.
Next and last is Italy.
Somehow managed to get to 3rd age in [08:55], that worries me.
I aged up twice with the advanced politicians card, so I got 9 musketeers and 17 settlers at hand at that point.
I had a fair enough position where I could either send “2 falcons” or the “black company” card, which would be a strong push against an unsuspecting enemy.
So yeah, USA has a quick ff, still, many civs can chase it with it’s own ff at a decent timing, or defending well enough while you get there (since 3 Gatling guns ain’t a siege party).
2nd age options don’t totally suck, a successful defense against an early push would leave USA devastated since it wouldn’t have the economy to just bounce back after investment.
Then again, if you don’t hurry up, you are screwed, fun experiment.