I regret I have to disagree with you on this one, Katitof.
I think it was easily possible for English speakers to become immersed with the Wehrmacht or PE in vCoH, bcs the lines the models spoke were amusing, and by no means a caricature, (though I am aware that some native German-speaking posters did disagree). In fact, if the lines were only pure caricature, I do not think they would have worked as well as they did. And the voice acting was of a very high standard (IMO).
When I consider the Ostheer/OKW on the other hand, the 'magic' seems to have evaporated to a degree. The Ostheer commander, for instance, seems far more harsh and therefore less empathetic, and less immersive. If you were going to argue 'parody', the Ostheer commander seems more prone to this criticism. The voice is harsh, it grates, and so lacks empathy, which (IMO) affects immersion. But that is my point of view, and it is highly subjective, I accept
I feel that is immersion breaking when they use all these corny lines with crappy accents. I am playing a war game, not a goofy arcade shooter. The campaign was quite cold and gloomy, so I think they should've matched that tone with more serious dialogue.