Steps to reproduce the undesirable behaviour:
1. Open two non-overlapping xterms on an empty workspace, not far apart
2. Form a group consisting of these two windows
3. Move them to the right edge of the screen (with positive edge resistance)
4. By repeatedly moving the group a little to the right, you can make the two windows overlap more and more.
I'd find it more useful to move windows by the same (x, y) difference [i.e. the same output], rather than by having the same force or acceleration applied to them [i.e. the same input].
Mass closure: This bug has been untouched for more than six years, and is not
obviously still valid. Please reopen this bug or file a new report if you continue to experience issues with current releases.