DGen Expert to the rescue...
indeed, DGen is a fickle beast. It can have its own ranks and its own aircraft names.
It is managed in the files named Message*.dat inside the DGen folder. These files are language setting dependant and manage all the briefing texts you get generated.
The DGen.exe campaign generator generates new missions based on a set of data and mission template files, as well as briefing files. These files are all contained in the DGen folder within the game’s main folder.
For it to work, it needs the following combination of files to be available and working in harmony together.
• Briefing files for campaigns and missions: these are “message” .dat files. There are notably pf_messageNA.dat files for Pacific Fighters, messageNA.dat files for Eastern Front IL-2 campaigns, NN_messageNA.dat files for French campaigns, GB_messageNA.dat files for British Western Front campaigns, US_messageNA.dat files for US Western Front campaigns (NA = nationality reference in 2 letters, e.g. “fr” for France). In your DGen folder, you may find more of these files for other nationalities (e.g. Italy, Hungary) or particular careers (e.g. British Hurricanes in Murmansk).
aircraft names displayed in briefings are managed in a section looking something like this:
<BF_109F2> <BF-109F2>
<BF_109F4> <BF-109F4>
<BF_109G2> <BF-109G2>
...
However, I didn't find a mistranlation of G2 vs E7.... so it probably was Emils you were dealing with.