> There are also countless ways he could have justified keeping Arabic in. For example, by saying the Koran ensured that there would be little linguistic drift,

> There are also countless ways he could have justified keeping Arabic in. For example, by saying the Koran ensured that there would be little linguistic drift, or at least that the drift would have some limits to it. That's even Frank Herbert's own justification in one of his appendices. Herbert seemed to have dabbled in conlangs a bit more than his contemporaries and put a lot of thought into it and picked the language smashes he did for thematic reasons, but with something of a semi-studious hobbyist eye for language drift. He detailed a lot of those notes in appendices. Given how much JRRT contributed to the conlang field in appendices, it seems surprising a conlang enthusiast would have missed some of the salient points in Herbert's appendices.