The flow of this story is all over the place. I actually like the idea of sending someone to another world without some sort of OP skill where they can only rely on their naive knowledge about war from their regular studies in an all but peaceful slice of their old world, but I feel like the story I'd rather see is how he copes with that when it happens, not 3 years later when he seems to already be in some army with one of the king's daughters effectively doting on him, and a half formed harem.
It feels like they really did write his introduction into the world, but then just tossed the first 15-20 chapters and started us on the next chapter after.