Surname Armani, Armano, Erman, Ermanno and others

Armani, Armanetti, Armanetto, Armanini, Armanino, Armanni, Armanno, Armano, Arman
According to Ettore Rossoni, all these surnames have their origin, directly or through hypocoristic forms, from the Lombard term Harimann or Arimanno (free men). The Arimanni constituted a form of patriciate who had the responsibility of maintaining the power of the King in the occupied territories. Similar to the equestrians of ancient Rome.
Alinei & Benozzo add these surnames to the list above:
Ermanni, Ermanno, Ermani, Ermano, Ermanis, Erman, D'Arman
and consider that these surnames derive from the Germanic name Armanno or Ermanno, formed by harja = army + mann = man. That is: free man belonging to the army, with the task of defending strategic points and inalienable rustic places.