negotiations are always possible, and probably ongoing. the thing is that when push comes to shove the bigger guy(in this case any of the 5 families) will almost always get the better of the deal. kinda like how america is when dictating foreign policy. we will listen to the other guys, but at the end of the day its's what we want.
Seems to me there was one aspect of the Sopranos that was true: joint operations. They were always partnered with the Lupertazzi's in various scams. I wouldn't be surprised if that's how Jersey made a good majority of it's money right now. But from what I hear they do have a fair amount of guys on the street.
"Don't ever go against the family again. Ever"- Michael Corleone
we will listen to the other guys, but at the end of the day its's what we want.