I'm not a Quinn fan but she's grown up in the drugs world so she's hardened as much as Vinnie who seems to be relatively new to the game, and both Quinn and Vinnie have the same supplier so answer to the same boss, no reason to think Vinnie has thugs that are not going to turn on him if their boss sides with Quinn and tells them to.
Hmm, that's strange. It seems to me that Vinnie is the top level supplier. Q gets her stuff from her uncle, who gets it from Vinnie. Before that, Q got it directly from Vinnie or from Tommy who got it from Vinnie. Not sure about that hierarchy though. It is clear however that Vinnie is upset that he has lost customers to Q, and he is feeling a need to do something about it, which as others have said, is strange, since everything comes from Vinnie anyway.
In any case, it seems to me that if dpc wants drama, nothing is going to beat death of Riona. Guys around here are muttering to themselves about how dpc would not dare. Hah. Me too, Riona is just about my fav, since she sees good things in MC that others do not. Same thing with Elena, after talking with him at the dinner table about his love interests, she sees something good in him. Things that he has not fully developed in himself, but there is a good chance he will. And the fact that they see that says good things about them. So, yeah, dpc, Riona better not die, of all people.