I also think that the characters were written that way to underscore an important subtheme: "No honor among thieves." If the Mafia is an "honored society" and Mafiosi are "men of respect," where's the "honor" and "respect" these guys are supposed to show the new boss? And where's the "honor" and "rspect" Tony showed Feech after Feech got to be a pain in the ass?

Ntra la porta tua lu sangu � sparsu,
E nun me mporta si ce muoru accisu...
E s'iddu muoru e vaju mparadisu
Si nun ce truovo a ttia, mancu ce trasu.