Let me try to sort things out as far as I understand the situation. You may also want to read my comments on the german GalCiv2 - Endless Universe:
https://forums.galciv2.com/328047/page/1/#2003899
The german retail release of the original GalCiv2 Dread Lords (DL) was distributed by Paradox. If you install from disc the game is localized and you can register it on Impulse (Stardock Central before) to get updates. If you download updates from Impulse, it also updates the german language file. Some showstopper bugs of the release version were fixed that way, but the translation was very poor and still has some flaws. As a custumor friendly option you are also able to leave the disc alone and install the english original using Impulse., but I don't know if the german language files are availiable for customers from Germany who bought the english version online.
Then Stardock released the two expansion packs Dark Avatar (DA) and Twilight of the Arnor (TA) that both require the original game registered on Impulse. However there is no german translation of the expansion packs availiable from Stardock, no matter if you bought the german retail version of DL or purchased your copy online via Impulse.
The official german translation was done by I-Mod. In the beginning I-Mod felt like making it public as soon as the german retail version was finished and released by the new german (and some other european countries) distributor Kalypso. As Paradox still had the rights for DL, a standalone bundle version of DA and TA named Endless Universe hit the market. Unfortunately Kalypso exclusively owns all rights on the german translation and I-Mod were not allowed to publish the files.
So to my understanding (only from what I've read in the forums) there is no legal way to get the official german translation if you didn't buy Endless Universe (or the soon to be released Ultimate Edition) from Kalypso. I-Mod and Stardock are not allowed to make it availiable.
