People don't have to have monolithic national identities. In fact, those cause problems, look at the Balkans.
The greatest missed opportunity of the Hapsburgs of the nineteenth century was not creating an Italian Confederation styled after the German Confederation. They could have had sole control over things like the military. Italian unity was Napoleon III's pet project but in a timeline were he were deposed, France many never become the champion of Italian Unity. Sardinia-Piedmont is too small to defeat the Hapsburgs on their own. So Italian unity without Piedmont would either have to turn to revolution or compromising with the Austrians. An Italian yet not sovereign confederation would be enough to pacify the nationalists (for a little while) and have much stronger regional identities among the Italians in general.