Chris Tolkien didn't really write anything new from whole cloth, he mostly deleted or married his father's notes and short writings; more editing than creating.
Brian Herbert wrote multiple books from scratch. His father left notes too, but nothing that would give him the ability to write multiple novels.
Nah, Brian seemingly put his name on it and outsourced the writing to Kevin Anderson. From the quality of story, it looks like he outsourced it to the highest bidder.
According to his bio notes, Brian is an “acclaimed author” in his own right. Why then outsource to the likes of Kevin Anderson?
He absolutely ruined the books and turned them into “churn them out” fiction.
Brian Herbert wrote multiple books from scratch. His father left notes too, but nothing that would give him the ability to write multiple novels.