Again 100% agree. If you are able to show the water sellers that would be great.
Related to narration, perhaps the cutscenes from Dune2000 (game) offer something usable.
https://www.youtube.com/watch?v=D7Is3sVVniQ
For example, around 29:00 they talk about the shield wall being breached.
The visuals are too low resolution but perhaps the audio is usable.
You also have cutscenes from Emperor: Battle for Dune. Here are some:
https://www.youtube.com/watch?v=NYYq-t90rQM
https://www.youtube.com/watch?v=eODItHK7wbM