Actually, one addendum I want to make, look at the beginning of this video, you'll see what I mean:
Youtube: arm drag
I didn't watch the entire video, so I can't vouch for its contents, but look at the first couple seconds.
To extent his reach (arm connects inside upperarm) and rotate his body- to what we call his third point - and take his balance. When I watch a bit further I see fragment of how we start shihonage. Also he tends to move around the center of movement. We make ourselves the center of movement. Aite is more or less a satellite in our approach. Would this be exemplary of IS applied in technique?