Since this story heavily references the German wars of unification, with Elfind being Denmark, then what's most likely going to happen is the same as in 1864. Orcsen will steamroll Elfind because of superior numbers and technology.
The question I'm having is how and if they're doing the other two wars, the German War and the Franco-Prussian war as well. A side story with the rise of Japan was also hinted last chapter.
not only that. the author throws in two references from a Cornelius Ryan book. we have the Nijmegen bridge crossing from A bridge too far and the soldier wearing his boots the wrong way from The Longest Day