Audiobook samples for narrator

If you’ve sent samples to a narrator prior to recording an audiobook, how did you decide which samples to send? Mine has told me the sample can be anywhere from a few paragraphs to a few pages, whatever it takes for me to feel confident that he can do the project well. But I have a lot of characters, and several of them are major/important characters. I also want to make sure to test his range with female voices. At this point, I’m definitely overthinking the whole thing, but I’m wondering what others’ process was for choosing dialogue and action samples.