I don't care if others think this is unrealistic.
I'm 66 so I was around during the turbulent years of the Vietnam War. My older brother served and by sheer luck, returned home. 58,000 American men didn't. the realistic aspect of this film is the emotional impact as we see the horror of war. Everyone that I knew that saw it in theatre, including me, were sobbing by the end of it. Not just crying a few tears, but emotionally devastated.
I think that this film, Paths of Glory and Come and See are the best anti war movies ever made. But that's just me. I in no way resemble a professional critic.