I'm not so sure about that. We already saw that while her past as an upper tier white collar does help her tremendously, it can also lead her to a trap. Running a department of a corporation is not the same as running a country or the military. Yet due to her grooved thinking, she can open her mouth before she can think things through. Realistically speaking she might be able to offer semi-educated pointers based on what she knows of our world's history (even so, she's Japanese, not European), but it's likely they won't help that much. Even Germany would have fared much better if it hadn't fought pretty much everybody else, but who could have made Hitler believe that before shit hit the fan? Not that it would have been up to them entirely either. Stalin was just as crazy and hungry, so it was only a matter who began it first. I suppose in this show's world things aren't necessarily that different, even if it's more like Strike Witches in the sense there are no nazis or communists.
Not to mention she almost slipped out that in the back of her mind she already thinks Germany is destined to lose, just like it lost in our world.