Before i dig deeper into planning for a complex Mod with multiple Factions & various gameplay twists and possibly Campaigns... i must know if the following quote from the Wiki guide is still active to help us out with the necessary XML schemas or whatever else could be achieved. (From March 2016 by Cari)
Note: This will create a binary file in order to have the faction available without restarting the game. This means that you will not be able to edit the parameters for the faction outside GalCiv 3 in XML format until Stardock decides to create an export to XML function. If this matters to you then see the other methods of mod creation on this page.
I somehow managed to inspect the ingame Faction Designer toolset but it seems a bit limited in scope while not providing any hints or facts on the "Packaging" of such mod.