For starters, the presentation is fantastic. The scope is also impressive. The card system seems pretty well thought out and I'd absolutely be interested in giving it a shot. Building the Havoc Engine objective system into a fog of war card that gets progressively revealed is both thematically interesting and feels like it would allow for this to be replayed several times showing the different ways war can play out.
Implementing the "lethal" roll to demonstrate the brutality of war is a great idea. It goes against the grain of the havoc engine's premise that you play as larger than life killers by making your characters replaceable, but that helps to drive the theme. I do wonder if that impacts your ability to connect with a specific character and roleplay their emotions and actions, but I think adding the Regroup actions/cards helps to alleviate that issue. I wonder if it would make sense to have a Mourn regroup action (or a subaction contained in Gossip) in which the characters can acknowledge those killed in the previous battle phase.
Another bit that I really liked was the "trench gong" promotions. What a great way to work in a bit of history into a mechanical element of the game.
As a final note, the choice to make this a game about struggling to achieve seemingly random objective passed down from on high, rather than giving the players a discreet objective to accomplish and all the tools they need to get it done is definitely thematically appropriate and interesting. I really enjoyed reading through the document and would be happy to give it a try sometime.