Like the first volume, Plus Ultra is long for a light novel. None of the books in The Saga of Tanya the Evil are quick reads. They take about as long as a standard western novel. For readers who watched the anime first, Plus Ultra goes from partway through Episode 5 to partway through episode 11. There is also a side story at the end which the anime shows at the end of Episode 2. This is where The Saga of Tanya the Evil differs from many other anime adaptions of light novels.
Typically, an anime adapted from a light novel tries to match pace with the books. This series does not do that. The end of an episode does not necessarily coincide with the end of a chapter. The pacing is readjusted for the anime adaption and while that is not necessarily a bad thing, it is unusual. That being said, it could even be viewed in a positive light depending on your outlook. The alternate narrative techniques used by the anime tell the same story, but in a different way. While the book has more focus on geopolitical analysis, the anime more focuses directly on fighting and warfare.
With all that in mind, Plus Ultra continues to be an already impressive series. This is the point in the story where WWI and WWII analogies start to mix. The first book showed more of the WWI side of things with notions such as the geographic location of the Not-Europe nations and trench warfare. Plus Ultra starts driving WWII-era points home, such as the application of new technology and tactics on the battlefield. All of this is obvious to Tanya, who is from Earth and has knowledge of WWII history. But to everyone else in the world, this is all new.
The Empire is newly established as a potential world superpower. However, they are surrounded by other countries on all sides. While their country is not landlocked, areas the size of the English Channel are the only waters between them and other nations. Some of these other nations are superpowers and want to prevent the Empire from becoming one as well. This is where The Saga of Tanya the Evil differs from real history. The Empire (Not-Germany) is always the defender (thus far). They have yet to attack first. And their military leaders 100% expected any potential wars to happen that way. How their plans of national defense will ultimately turn out in the face of a reacting enemy remains to be seen.