Quoting Lord Xia, reply 139 thousands and thousands of turns.
Carl Sagan, you are not. But I bet Carl Sagan never had a pony.
It's a popular misconception that Carl Sagan used to say "billions and billions". He never actually said it in the media, even though there is a unit of measurement called Sagan, which is defined as "at least 4 billions", the minimum which "billions and billions" could mean.
Anyway, I am pro-governors, because even on a medium map I get to the point where I need them. I never played a large map, since a medium one is large enough. The truth is the game gets kind of boring when nearing the end, and micromanaging conquered cities adds to that monotony. Leaving the cities to idle is saying that you just don't care anymore, which indicates you got tired of improving them, which is where governors come into play. On the other hand, the number of cities in FE is not that huge, so giving them a queue and leaving them be is an option.
GalCiv 2 only got governors after release, but then again, you can have over a hundred planets on a large-huge map, and more on an immense map (governors were already in when they made the immense maps).