I'm trying the group target component and puzzled by the results: I've set up 2 characters, 1 looping an animation. I've used the 'Create Target Group Camera', and use the hip bones from each character: Here's the camera set up: Why is the camera swaying so much? The center point (yellow dot) is staying between the targets as I would expect.
It's probably because the group has "Group Average" as rotation mode. It's setting its rotation as the average of the rotation of the members' hips, then the transposer is positioning itself in the group's local space. Set the rotation mode to Manual.