I have to ask a question about "Major" Cavalcanti. It's not very clear as to whether the slightly confused old man really is a Marquis/Major or whether he's the Count's invention. The dialog in that chapter is hilarious, where the Major looks to the Count to "remind" him of his cover story. So, by the end of the chapter, and the adjoining Andrea chapter, the Count is paying them off very well to act as father and son.

Is the Major for real, with a real name of Cavalcanti, but fallen on hard times?

Are the old man and Benedetto impostors, using the names of a real, noble family Cavalcanti? The old man is a just former soldier who needs money?

Or are the Cavalcantis the Count's invention, but then wouldn't Danglars send inquiries to Italy and check into that "family" and their titles and income before committing his daughter Eugenie to a marriage with that family?