I don't understand. In your submitted game you say you won in the 1400's, and then in this one you won in 1400. How many turns difference did you gain? Did you Oracle Mach in both attempts and just removing mistakes to see what could be acheived on that path, or did you try the alternative (CS-sling) and make comparison?
Frankly, I think 1400's domination is very fast for a map requiring Astronomy. Fast war is one thing, fast tech is another, balancing/alternating the two is always tricky.
My submitted game was in the later 1400s - I like to keep things ambiguous.
I was actually pretty surprised that my 2nd try was not faster. I used Oracle for Mach in both attempts but did not bungle bulbing techs with Great People in my 2nd attempt. That got me Astro a bit faster, but not by as much as suspected.
I also ran a cottage econ in the 2nd game vs. Specialist econ in the 1st game. I think the specialist route may have been a better bet though. Even with financial, cottages take a while to develop and in the 1st game building the pyramids and running representation was pretty effective.
The other difference between the 2 games was warfare.
-I game 1 I took out Monty with HAs. In game 2 I did this with Axes. In game 2 I also kept the Aztec capitol rather than razing it and rebuilding it on the optimal coastal location.
-In both games I attacked Egypt a bit too soon and had to wait for reinforcements. But I think I was a bit faster in game 1 as I was building more HAs which could get to Egypt faster.
-In game 1 I took out Japan 1st and then boarded ships to attack the Mongols followed by Persia and lastly Greece or Spain. In game 2 I went for Spain and Greece right after I had Astro and then went after Persia. I took out the backwards Japan very quickly with knights as I was mopping up Persia. I am not sure if going for Japan 1st or last was the better strategy. The luxury resources were certainly useful to keep people happy, but it is more efficient to take them out at the end as otherwise you end up with excess units that cant sail over to the 2nd continent in time to make any difference.
A limiting factor (in both games) was $ to upgrade galleys to galleons, HAs to knights, and axes to maces. In game 1 I had $ from capturing Japans cities. In game 2 I had a better cash flow due to the cottage econ and fewer cities.
I might try the game again with a CS Oracle sling.