Aren't we splitting hairs a little bit here? It's 11.0% in the Northeast, and 10.6% in the southeast. Perhaps a distinction without a difference? Also, as I've said elsewhere, I admire the work of Boattini et al, but this is one study, and the number of samples in any one area is not very large. I think a more balanced picture would include other sources. I think it would also perhaps include some of the other subclades of M-78. Just as an example of why I think some of these Boattini et. al results may be a little skewed, I don't for one minute believe that E-M81 really has its maximum in Bologna or in Emilia-Romagna in general. They just happened to scoop up an M-81 line there.
What I think is fair to say, however, is that y dna E-V13 in Italy is either through direct settlement in the Neolithic or through Greek colonization in the first millenium B.C. How to distinguish between them, would require, I think, dating different subclades within the larger E-V13 clade. As for the E-V13 in Liguria and Piemonte, I would be very surprised if it was mostly Greek mediated. There were never the large scale Greek settlements here of the kind that were present over much of the Sicilian and coastal southern Italian areas. The southeast probably would contain E-V13 from both expansions, as might the northeast, although more of that is probably Neolithic than in the southeast.
I think it's also fair to say that it is surprising how much E and G and J2a there is in the northeast. Rather funny as well, for all those who try to link phenotype with y dna clades, and hold that these three clades are Middle Eastern and therefore supposedly confer "darker" phenotypes, as the Veneto is perhaps one of the fairest regions of Italy.