Chin chose QD to handle things before he died. They go all the back to thier boxing days. Chin's word still carries weight. Chin was pure power. QD has and will never be exposed via wiretaps/tapes. Hence the nickname. Barney and/or a panel 'actively' handle the business on the streets. When Leo gets out, he may or may not take up a leadership position beyond his own crew. The complete picture will not be known for years, if ever. OC is supposed to be a secret society, and the Genovese Family is one of the only ones left that adhere to that premise. (Detroit being the other)