You should look at the map. Val d'Aosta and Trentino-Alto Adige are small underpopulated alpine regions and they mostly produce skiers and winter sports athletes, or cyclists. Molise is also small but on the Apennines, lots of sheeps. From Val d'Aosta the only good player was Sergio Pellissier, from Trentino there's Pinamonti now and I can't remember any other players. By memory I don't remember any players from Molise, I doubt more than a dozen have made it to the serie A.

Molise it's a meme in Italy for it's irrelevance to the Italian landscape (be it political, cultural,sportive,...) and people meme it doesn't exist and that it's actually fictional like Atlantis and similar fake regions

Trentino-Alto Adige is the part of Italy that includes South Tyrol and athletes there are more focused on winter sports, some exceptions exist (Sinner with tennis but even him was a grand slalom winner before choosing tennis over skiing) but are rare.

Valle d'Aosta is a fully mountainous region (between France and Switzerland) and has the lowest population in Italy because of its size and rurality. Athletes are rare and like Trentino usually going to practice winter sports instead of footbal.

The last four regions are the least populated, the last two are the smallest. Basilicata has quite a number of matches because of the unforgettable Simone Zaza (18 with two goals scored)

My father was born on the border of Abruzzo and Molise. There is nothing there, even today. Small little towns and lots of sheep, mostly. But funnily enough, it's becoming a tourist destination because of how 'traditional' it is so that's something