You didn’t have an argument, you had a sequence of hypotheticals, some of which were easily googled for a wealth of contemporary scientific studies exploring those very phenomena. It’s clear that you have some personal attachment to rejecting the scientific method and our best understanding of the causes of stuttering, as you would otherwise not make general references to the opinions of speech therapists when confronted with overwhelming amounts of actual research. I honestly just hope that you think twice before suggesting somebody to “read more books” when you yourself have such a tenuous relationship with scientific thought.