I would tend to agree with you here, with a caveat. All these theories are describing the same underlying phenomenon so there is a "blind men and the elephant"

I would tend to agree with you here, with a caveat. All these theories are describing the same underlying phenomenon so there is a "blind men and the elephant" effect. They also substantially build on one another The caveat is that what really sets these models apart is how they propose to navigate the mind. This is where I believe IFS stands out. But it would take a much longer comment to explain that. Maybe it's worth writing an article about.