Could someone help with this?

Start pos changes only work for rome.

So I have recently returned to playing rome 2. I was looking to modify an alt history grand campaign onto the imperator augustus map.

I created a new faction the way I knew how but this didn't work. So I resorted to modifying existing faction names, culture etc. I updated the region ownership table to find the changes made no effect. So I reattempted with Rome and found on both grand and imperator the changes worked but not for other factions.

Does anyone know what is causing this?