Is this based on the v5 or prior iterations? The percentages would change.
Based on what I've seen of v3 results this looks right.
The demarcation for a lot of these clusters isn't south of Rome, it's south of Toscana. Northwestern does reach to Napoli.
The British and Irish are perhaps connected to Gallic migrations of the first millennium which entered Italy from the northwest?
There's virtually no "Eastern European" in Italy, despite what some of those calculators say.
I thought the "centrum" for "Italian" in 23andme was the south in the past and perhaps Toscana in 23andme but it seems heaviest along the Adriatic, in parts of Marche, Abruzzo, and Molise, where, incidentally, there are high percentages of J2. So, southern Italy, but not Calabria or Sicilia.
The "Balkan" cluster, as we've often discussed, runs east to west. Another interesting thing is that it also peaks in a lot of the areas where J2 peaks, which is not Calabria and Sicily, but places in Central Italy and the more northern parts of Southern Italy, along the Adriatic. That's another factor in favor of an entrance of J2 into Italy from the Balkans.
Italians get no Sardinian. As I've been saying ad nauseam, they're too drifted.