How did Arab raids contribute to the formation of the Sardinian giudicati?

The formation of the Sardinian giudicati was not a direct result of Arab raids in the sense of a planned administrative transition; rather, it was a consequence of the necessity for local self-defense.

Beginning in 711, Arab raiders launched repeated assaults on Sardinia throughout the 8th and 9th centuries. Because the island was increasingly isolated from external protection, the Sardinians were compelled to organize their own defense against these Saracen incursions. Historians believe this urgent need for autonomous military and political organization likely led to the emergence of four self-governing giudicati (or "judiciary circuits"). While the specific history of this period remains somewhat obscure, these divisions eventually evolved into the distinct political entities of Cagliari, Arborea, Torres, and Gallura.1