Khuzdûl based on Hebrew

Anyone who has studied Hebrew knows that its three-letter noun roots is the core of an exceedingly elegant system. But actual use of the language (as with any language) has led to many exceptions to the rules for common words.

I recently read that Tolkien used Hebrew was the basis for his Dwarvish tongue, Khuzdûl.

Now I wonder if he, as a linguist, found it more satisfying to keep the three-letter root system elegant or to be realistic and insert into Khuzdûl "degenerate" forms for common words.