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.
I’ve read “Killer Angels” and watched “Gettysburg” (several times each!), and I concur with your analysis.