I have no idea, Markod, but that would mean that Umbria, Marche and Lazio all get lumped into South Central Italy?
Also, in that particular graphic, NCItaly 1, 2, and 3, are pretty similar. In others, there are differences. If they actually got samples from the Lunigiana and the Garfagnana, which are in Massa Carrara, they would definitely pull away as they're more like Emilians and eastern Ligurians.
Without the key and the list of samples and their sources, we're a little bit in the dark.
As to Sicilians, as I said recently on another thread, Southern Italy never got the Lombard migrations of the Middle Ages. I'm skeptical of "Norman" influence. The original "Norman" invasion was a couple of dozen knights. More people came from France during the "Lombard" sponsored migrations, but that's a different issue.
https://en.wikipedia.org/wiki/Lombards_of_Sicily
Still, it's not enough to pull them very far apart from the Calabrians, which makes sense given they were ruled by one entity for hundreds of years, and there's been so much movement back and forth across the Straits of Messina.
With all the talk on the other sites about Levantine migration, I checked again. I don't see any analysis using Levantine Bronze Age. Maybe too much overlap with Anatolia Bronze Age? Look what happened when they used Peloponnese Neolithic.
The only mention I see of the Levant is in one of the Chromopainter schematics, and as the authors themselves seem to recognize, until we get ancient dna it's hard to figure what came where. It only applies to one part of Sicily, however, so, perhaps with the "Moors"?