I could pick several examples of macro-level editing in my own writing. The best example I have is from the first novel I ever wrote - a deer-hunting horror story that I wrote back in college. The reason this one may be the best to choose from at this point is because, as a writer in the pre-infancy of his career, I was naive in the realistic-ness of the story. Certainly, with it being horror-genre, it's a story that could never happen, but in that world under those conditions with those characters, would the overall story be realistic in how it emerges. Turns out it doesn't.
The gist of the story was a group of four friends who go out hunting each year in the wilds of northern Minnesota, and they found themselves immersed in a killing spree with an undead monster--who just happened to be their best friend who went missing years ago. Anyway, in the story, the monster killed between thirty and forty people.
Do you see a problem with that?
You may not, but if you were to thread that with the rest of the story, it was all up to the local Sheriff's department to solve, without the help of the FBI or even the Minnesota BCA and without the governor calling in the National Guard to keep the peace. Also, if there's a killing spree nowadays that involve even a handful of people, the media flocks to it like flies on shit. In my story the media was non-existent. Not that I needed the media, but I should've at least written a little about it.
In the end, the number of killings were greatly reduced - it's a novel that needs a lot of work (for crying out loud, it was my first novel; of course it's going to need a lot of work) but it will be published some time down the road.
I could go on and on with examples, but for now I'll leave it here.