For example, I view kuzushi as a prerequisite to aikido; that is, I cannot execute an aikido through unless I have kuzushi. Morso, if I have kusushi I can execute a number of throws, including aikido throws. So for me, kuzushi is what I would define as a pre-aikido curriculum.
I always thought of it the other way around - that aikido is a particular system of principles and techniques to get and keep kuzushi, and that there are other systems that are similar in some ways and different in others. Once you've got really good kuzushi it seems like that's the point where you're basically finished the technique most of the time? If you keep doing more after it's basically henka waza, isn't it?