There is no meaningful commonality between attaching as in hitting someone in the head, and attaching as in making arm "bridge" contact. No reason to classify these things as part of some set other than seeking to interpret the terminology in a way that is not contradictory.
Seeking bridge makes no sense if you interpret it as seeking attachment (however tenuously defined) because all attachment is attachment, there is no differentiation between useful attachment (fist to face) and useless attachment (arms joined). Seeking attachment also entails sticking, because if you become un-attached, then you seek to become re-attached. All of this leads inevitably to hand chasing.
The only interpretation which makes sense of the second form and how it fits into the system in a coherent way is that it is teaching how to find and make attacking lines. And this is what it does, in terms of content.