The Blood of the Eagle and Lion is really stupid no matter how you look at it. I have some comments regarding it, but it contains miniscule spoilers regarding the Blue Lion route, so if you don't wanna know anything at all, don't read.
You play The Blood of the Eagle and Lion on both the golden deer and blue lion routes. Marginally it makes more sense in the golden deer route, after you have played blue lions, why Dimitri would act like he does. Marginally. In the blue lions route there is literally no logic as to why the golden deer house takes on the antagonistic role that blue lions have in the golden deer route. The game's pretend reasoning in both cases is that Edelgard is using her shamans to create so much chaos and confusion on the map that they cant tell friend from foe, but that makes no sense when characters exchange dialogue before engaging in battle, and if that was the intended logic, there is no indication of it on the battlefield. I don't like fog of war gameplay, but at least it would make sense in the narrative to have some presence of that at play, but they don't, and there's no visual indicator of such a situation. It's by far the low point of any route the chapter appears in.
They kind of didn't know how to make the 3-way POV thing work. The narrative would probably have suffered less if it had been Fire Emblem: Two Houses.