Re: Have Steam dumbed down the Alexander exe file?
The slave faction is essential for game mechanics and has too many pitfalls to be able to be played.
The pope is a special faction as well (see descr_sm_faction entry) but can be played. A lot of mods simply remove the faction if the pope is irrelevant to it.
Disabling\deleting the special_faction entry in the pope's faction will reduce it to a regular faction. Beware of the family tree setting.
Which leaves another 29 (30 if you modify the pope) regular faction slots to make a total of 31 factions.
You can use any regular faction as 'labels' for places of interest (see the named fort principle) - just obviously not one that is playable.