One doesn’t need to “believe” Prof. Pio, rather one needs to acknowledge the evidence preserved in the historical archives. I tend to run a mile whenever people talk of “”Germanic features”,even if they are just quoting some grotty book.
One should also understand the Füssen system. There were relatively few violins actually made in Füssen, rather they “exported” 13 year old boys to relatives in far away places, who subsequently learnt there. I had an attempt at explaining that here https://maestronet.com/forum/index.php?/topic/361833-johannes-albrecht-violin-identification/#findComment-1038209
This “export” of young boys went in all directions of the compass. The Easterly axis of this compass for instance went along the Danube to Vienna and beyond. The south-Easterly axis went through Innsbruck, Bozen, Paadua and on to Venice, the Southerly towards Rome and so on. Venice was a centre of what I would call ethnic Füssen violin makers, even if some were born there. A thirteen year old boy doesn’t bring any “Germanic” scroll carving tradition with him in his luggage.