These are the best client situations. A presenter who has delivered a story a thousand times, the story flow is great but completely disconnected from the (poorly designed) slides. When I receive the existing slide deck without explanation I cannot make much of it. But as soon as the presenter ads the verbatim (“This is what I usually do...”) a powerful story comes out that is usually told over slide 1 of the presentation.
When redesigning a presentation, start with the audio track and ignore the existing slides.