Why Accardo and Gambino..? They were more shrewd than ruthless.
I don't know about Gambino, but Accardo showed his personality with what he did to the burglars who robbed his house. Accardo is really a strange combination of criminal genius and occasional psycho.
I think most mobsters would have taught them a lesson
I disagree. Most mobsters would not have ordered six murders over a burglary.