WordPress looks for the most specific template first. For a custom post type 'book', it first tries single-book.php. If that doesn't exist, it falls back to single.php, then singular.php, and finally index.php.
For category archives, WordPress first looks for category-{slug}.php before category-{ID}.php. Since both exist, it will use category-news.php.
The correct format for author archive templates is author-{nicename}.php. Underscores or missing hyphens are invalid.
If the taxonomy slug used in registration differs from 'genre', WordPress won't find taxonomy-genre.php and will fall back to archive.php.
WordPress uses the slug of the current page to find the template. For the child page 'team', it looks for page-team.php first, regardless of parent page templates.