A good COPY EDITOR will still look at issues of pace, but they will focus at the level of individual sentences and paragraphs. Are you using unnecessary verbiage? Or is this scene underwritten? They’ll spot if a character’s eyes change colour part way through the book. They will also check (or at least question) factual detail. (Was the model of car you describe available when your story was set? Is it really possible to shoot someone at that distance with the gun you’ve given your villain?)
Perhaps the best analogy here is to a film editor, taking your ‘footage,’ spotting bloopers, and helping you to make the selections and cuts to hone your pacing, your atmosphere and the clarity of your storytelling.