Would it make sense to subdivide further regional, for instance into tags for Northern, Central and Southern Italian (and Swiss-Italian if the need arises)? It feels like in many cases OP already knows which of these variants applies.
I personally do not think it is necessary. We do not have enough questions with the regional tag to justify splitting it. Remember: to justify splitting a tag we not only need that the subject admits a natural division of the topic, but also that there are enough question in each of the subcategories to justify a separate tag.