It is not surprising at all...The Italian_Piedmont average is made mostly with samples from Val Borbera, which is near the Piedmont, Liguria and Emilia border, not far from NW Tuscany.
Check these
Alessandria,0.120652,0.148267,0.018102,-0.019703,0.033852,-0.004741,-0.00141,-0.005077,0.012885,0.02278,-0.008931,0.003597,-0.019326,-0.004404,0.003122,0.008088,0.014473,-0.00038,0.006034,0.00025,-0.001497,0.002226,-0.000739,0.005784,-0.00455
ValBorbera,0.1213354,0.1473534,0.0208925,-0.0145996,0.0292668,-0.0058844,0.0028435,0.0001615,0.0074653,0.0241279,-0.0002273,0.0063544,-0.0098859,-0.0045141,-0.0015744,-0.0027048,0.0011213,0.0008997,0.0021747,-0.0038269,-0.0025705,0.0018548,-0.0024033,0.0038316,-0.0014967
BorgoValditaro,0.120652,0.142174,0.026398,-0.020995,0.033852,-0.006693,-0.007285,-0.002308,0.00225,0.019317,-0.00065,0.014687,-0.006095,-0.003028,-0.004886,-0.00053,0.006519,0.004941,0.000251,0.002376,0.003119,0.005935,-0.001356,0.013496,-0.000958