Some things to keep in mind are that these are all 4-player games, and there's one rule change, which is that Korea's starting ability only grants it one architect per golden age, not two.
I mostly agree with what the stats show. Persia is very strong. Korea without the nerf is also very strong. Mali and America are quite weak. The one I disagree with most is Poland. I think it's stronger than its showing in the tournament would suggest. I'm not the greatest player or anything though, and still fairly new to the game.
America is far more powerful in 5er than in 4er, because Democratic Republicans hit in basic situation 2 persons (so the action is twice as good), there is more dynasties to affect (I mean more players means more opportunities) and books give more points. Just to say that player count and difficulty level affect quite much to nations powers.
It means that in Main and Open Divisions combined, 5 people who finished the game 2nd picked Sun Tzu.
Among these players, two were the first to go on first round (we can assume they picked Sun Tzu first thing), one was second to go on the first round, and two were 3rd to go.
I am surprised noone who picked Sun Tzu won the game during S3.
Can you explain the spreadsheet? Is it saying that no one who took SunTsu came first, and if you took the Sphinx, you only won if you were the third or fourth player?
Noone who took Sun Tzu came first indeed. But your logic for the Sphinx is backwards. It's not that the Sphinx is somehow better for 3rd or 4th player, but that picking it first thing as if it was a top priority wonder may actually hurt someone, especially with a more aggro board.