Why would Castellano want Gotti or Tommy G as his underboss? And Tommy isn't a street guy anymore than Castellano was, so I don't see Gotti liking him. I've said before that Castellano would of been wise to name DeCiccio as his underboss. DeCiccio was close to Castellano and respected by Gotti.

"I die outside; I die in jail. It don't matter to me," -John Franzese