If you have identified yourself in more then one of the characters in the dysfunctional unit, you are correct. Most people are primarily one personality and a little bit of another. They are interchangeable because if one is not there another person has to play that role. The healing that has to take place comes from the unit as a whole being able to be individuals instead of working as a unit. They encourage the individual to be all of these within themselves. Function comes when the unit can be all of these things and accepted into the unit no matter what happens. All of us should be able to make a mistake without having to blame it on someone else or cause the kind of stress and anxiety that happens when dealing with dysfunction. We should not need someone to be the stress reliever and no one should be hiding from the tension. If you make a mistake you should be able to learn from it with only natural consequences as a result.
Change can happen by allowing each individual to change and then coming together as a unit and create a new dynamic within that unit. It will not work if even one person does not change because that person will try to make things the way they were and cause problems within that nit until everyone is back to the dysfunction. Dysfunction is miserable but familiar, comfortable and you know how it works. Easy to fall back into old patterns. You will have to be determined in order for this to work on a permanent basis. Fortify yourself with meetings and therapy. All dysfunctional have PTSD symptoms and should be in trauma therapy. Giving away things you have no control over will help. Here is my guided imagery video to help with that.