Sure. And you can have a slightly better kingdom of Two Sicilies with a POD around 1830, but it would be still a country crippled by centuries of bad management. Go back a few centuries, and the southern kingdom is a much much better shape. Easier to build on strength than on weakness
As far as the Piedmontese: before Garibaldi's expedition to Sicily, Cavour's problem was to get support from France for the annexation of the Duchies (Parma, Modena and Tuscany) and of the papal legations (Bologna, Ferrara and Romagna). According to a certain view of Italian history, Garibaldi's move gave him the fig leaf of moving south to keep the "revolutionaries" under control. In doing so, the Piedmontese army took the opportunity to liberate also Marche and Umbria. There's another view, and it says that Cavour was very much against the annexation of the southern part of Italy, because it would have increased the difficulties of forging together a unitary state by an order of magnitude (something similar to Bismarck's reluctance in including too many Catholics in the new Germany). In the case of Cavour, Victor Emmanuel and Garibaldi forced his hand.