I've actually started taking a glance inside the worldbuildersave files myself, largely in part from me just being curious about whether my wild and unbased guess might be on to something.
One thing I have noticed is that in the Firaxis-made scenarios and such, there are specific details given for each player that actually appears on the map--for instance, the Earth.worldbuildersave file has the following for Mongolia:
Code:
BeginPlayer
LeaderType=LEADER_GENGHIS_KHAN
CivType=CIVILIZATION_MONGOL
Team=8
PlayableCiv=1
StartingX=99, StartingY=51
Handicap=HANDICAP_NOBLE
EndPlayer
Incidentially, Mongolia is the last "playable" player (out of a total of 9) that is listed--and I discovered that the entries for the "non-playable players" are identical to the entries for
all of the players in the worldbuildersaves generated by Atlas:
Code:
BeginPlayer
LeaderType=NONE
CivType=NONE
Team=9
EndPlayer
Thus, what's happening is when the game reads a map made by Atlas Map Generator, it sees that all of the players are "null." Obviously, that isn't going to work, so the game most likely resorts to assigning players based on the default players number that is appropriate for the map size that's assigned in the file.
What all this means is that the current way Atlas handles starting positions and player numbers is going to have to go under a healthy amount of experimentation--a way needs to be found to allow the civ and leader types to be randomly chosen when Civ IV starts a game with the file... And as far as I know, there really isn't anyone outside of Firaxis who knows enough about how the map settings are actually processed by the game to be able to give us a simple answer.
Maybe tomorrow I'll start playing around with the various settings, as they are described in
another thread, to see how the game actually processes the information in certain circumstances (such as CivType and LeaderType being set as NONE, but having the starting location coordinates declared with them instead of in the actual plot's settings).
EDIT: Disregard this, take a look below for why.
Hopefully something'll be figured out eventually. As for me, I gotta sleep
EDIT: I just happened to look through the entirety of the thread I linked to, and saw you'd already asked about that... Which means Atlas is probably limited to methods like randomly assigning CivType and LeaderType for each "real" player as a part of the file generation process, as opposed to trying to find a way to get Civ IV itself to handle it. ...I might still try messing around with the files anyway, though.