THE HARD WAY
1) Make a copy of the "Example Mod" folder in the Mod folder of your My Games Folder (where your Factions are). Rename this copy "Fixing Maps," or whatever.
2) Copy this file:
from C:\Program Files (x86)\Steam\steamapps\common\Galactic Civilizations III\data\Game to the Game folder in your Fixing Map mod folder. Do not change the name, do not erase the old one.
3) Open the COPY of MapSizeDefs in your Fixing Maps Folder with a text editor (notepad), and find the lines that say:
There will be one for each <MapSize> entry (and thus, one per map size). You can change these values as you desire. Save your changes.
4) Load GalCiv3, go to Options, and enable mods, restart.
5) When the game loads the next time, it SHOULD use the administrators you asked for.
THE EASIER WAY
Do everything above, but on step 3, just comment out the lines so they won't be read at all:
<!-- <BaseAdministrationPoints>4</BaseAdministrationPoints> -->
If you remove all of the "<BaseAdministrationPoints>" entries, the system will actually revert to using NO ADMINISTRATORS AT ALL. I found that out the embarrassing way.