Even FF had no formal training in Hebrew or Greek, he said so in Court.
The NWT has always been a "Version", never a Translation as it claims to be, they simply have never had any properly trained or properly accredited Scholar/s involved at any point.
Having said that, F.Franz had a fearsome Intelligence, and the Autistic person's ability to concentrate fully on his work, and he did very well, with simply using other already published Versions, and Bible Dictionaries etc. but of course, his weird beliefs coloured the final NWT, as such beliefs do to this day, in each iteration that comes out.