If you are feeling like it needs another rewrite, it probably does! That feeling is key to my writing method, especially if a chapter a do over to flesh out any details I might have missed the first time around.
For the most part, I rewrite as I go, so I don't really count the number of "drafts" a piece has gone through. Once the storyline is done, it's done, like @therosesword said . I don't worry about tweaking details, unless I get the feeling a story or a smaller set of chapters has to be reworked. When I get that feeling, I do a rewrite.
In my opinion, I wouldn't do a rewrite solely for the sake of "being realistic". The most "realistic" shows/stories have a team of writers who spend hours of writing, story consultations and more. In the 1970s, there was a show called "Emergency". It followed two paramedics on their adventures (it was a precursor to today's EMS drama shows). The show creators wanted the story to be as accurate (realistic) as possible in case kids tried to replicate the show, so they made their actors take paramedic training. I read somewhere that the actors were so trained, all they needed to do was take the exam to be licensed paramedics.
My point is that as long as you are trying to write the very best story you can, with the resources you have, readers will understand. If readers want ultra-realistic, they can watch the news. Trust your gut!