Ok.
so looking for actual data on this.
non verbal covers a wide range of situations.
firstly there are about 10.3 million under 16s. So that’s 343,333 classes.
Deaf children may be non verbal at least in the early years (although cochlear implants and hearing aids are having a big impact). There’s 45,000 of them in England
https://www.ndcs.org.uk/about-us/news-and-media/deaf-statistics
but 89% communicate with spoken language only ie they are verbal so that’s down to just 4,500 children.
that’s not even 1 per school much less 1 per class.
Autism - there are 166,041 autistic children under 16 in school. 30% go to special school so are not in mainstream. So 116,228 are in mainstream.
Just over a quarter of children with autism are non verbal or minimally verbal. In practice I suspect that this group is much more likely to be in special school but let’s assume for the moment they are equally likely to be in mainstream.
a quarter of 116,228 is 29,057.
England has 24,500 schools.
so on average that is just over one non verbal autistic child per school.