Why structural editing must come first
The expensive failure mode of AI-assisted books is beautiful redundancy: three well-written chapters making the same point. Line editing cannot fix that — only deletion can. Start from the table of contents, assign each chapter a one-line job, and enforce non-overlap. A 30% shorter book that always moves forward outperforms a padded one in reviews, and reviews are the compounding asset.
A practical test: write the reader’s question each chapter answers. Two chapters with the same question are one chapter with a costume change.