Note: assumption made that thought is in a particular language.

I can speak English and am learning Esperanto. When I think of the referent known by the English pointer "dog" my mind most strongly associates the pointer "dog" and much less strongly the pointer "hundo".

But as per internal narratives? I'd agree, yes, that articulating words, whether in an internal narrative or externally spoken, is separate from understanding.

I think what byrnema is saying is that they don't articulate their running internal narrative. They are developing an internal narrative along with the worldess-concept kind of thought that is already in place.