well, ultimately tanya was put in a parallel world set on one of the most violent periods of our own history. We should expect a bunch of key events to be mirrored with slight alterations on the basis of magic and this worlds unique methods of handling problems.
I still wish they won though... cause quite frankly, with someone like tanya participating, it seems almost impossible for a loss to occur... then again, tanya seems to get edited out of history, so I guess the gods are actively forcing things to play out a certain way? even going so far as to deny her existence in the future?
Unfortunately, I only know the story as far as the end of the anime... I would have so many questions answered if I started reading this manga after having read the LN first xD.