If we are really to take a serious look at the whys and wherefores of that map, I don't think that a world war has ever occured in the first place, in the Strike Witches world. Apart from this, even ignoring the fanciful alternative country names (speaking of which, Romagna still bothers me somehow) and assuming ad absurdum that all the historical events prior to Neurois' coming were not dissimilar from ours, I assume a more reasonable point of divergence can be traced back to, say, the second half of 1800.
At a glance, Italian Risorgimento didn't go as expected, which then butterflied into a more successful German victory in the Austro-Prussian war some years after and a merely half-done Balkan War.
Hmmm, maybe I'm overanalyzing too much. I need some sleep.