Jason Mroz’s review published on Letterboxd :
Chandor's biggest production to date and, in terms of direction, there's little here to complain about. Great camera work and sound design make this a showcase for Netflix's Ultra HD streaming quality. There's quite a bit of story here to process but ultimately the film doesn't seem to convey enough about its characters to bring a sense of empathy to the proceedings. There definitely a touch of The Sierra Madre at play which helps in giving us something relatable about these characters. A good deal of dialogue is invested in the idea that we can't quite relate to them at all given "the biological and physiological" effects of warfare. Where is the dividing line between that and greed? The film doesn't quite answer. We're not given some message here about the nature of warfare but instead a well executed production about some guys who did some thing - and that's fine.
An articulate attempt to explain the issues here: