Newt Gingrich and another guy (whose name escapes me right now) wrote a trilogy examining what might have happened had Gen'l Lee listened to "Pete" Longstreet. It is a pretty good read!
I read the book. William Fortchen (sp?) was the co-author and a Professor of History.
IMHO, they did a mediocre-to-good copy of “Killer Angels” by Michael Shaara. I highly recommend that book and the later movie “Gettysburg” which is incredibly true to the book.