An excellent and timely idea spoiled by cursory execution, partly to make a movie palatable--without De Sade-Cormac McCarthy-style scenes of unbridled sadism, partly to satisfy Hollywood political correctness censorship.
Good execution, and, probably an original idea was to remove any political hues in the contest of the warring parties. But Hollywood censorship bureau imposed the necessity to make the US Government side look like Trumpians -- third presidential term, disbanding the FBI ("intelligence community" is the darling of Hollywood neocons) and the only mass murder scene was obviously led by the MAGA men against immigrants and the people of color.
Henceforth, the movie incorporates an impossible "Western alliance" of Texas and California. The civil war situation strangely allows a practical exterritoriality to the war correspondents, even female. A realistic "Game of Throne" adage that "soldiers will f-[assault] anything with tits" of the Queen Cersei will be too hard to swallow by the sissy US audiences.
A turning of a naive girl (Cailee Spaeny) into a fearless psychopath and a violence groupie is sublimely acted upon by Cailee and the cast but it is not psychologically supported by other plotlines. Some psychopaths, like Cheney, Rumsfeld, Samantha Power or Joseph Stalin enjoyed mass murder but were largely averse to watching it and were quite cowardly. But there are also people, like Jungers -- whether Ernst or Sebastian, or Otto Skorzeny -- who were attracted to the gore and killing as to a drug, and got an additional kick from risking their own lives.
The war scenes are so XXth century -- as war in Ukraine demonstrates, an infantry movement without close air support by drones and even with it, over the enemy territory is almost impossible. So, a significant share of combatants have to stubbornly look into their phones and laptops.
Summary execution of the political elite is stupid. Wars must end with some form of the legitimation of the winning side. That's why, the Soviets did not execute Reich's military and political elite after the siege of Berlin and, moreover, offered them full protection against reprisals by Red Army soldiers, most of whom, in view of Nazi atrocities had ample reasons to do so. And, indeed, orderly capitulation procedures by the Allies precluded guerilla war and other manifestations of the failed state. On the contrary, unconditional elimination of the Iraqi and Libyan governing structures by the Americans paved the way towards a protracted civil war, lawlessness and partition of the respective countries.