Amongst office buildings in Canberra, on a nature strip with planted oaks I observed the DB Finch in a flock of Yellow-rumped Thornbills.
It wasn’t associating with them, it was actually part of the flock, following the others closely and seemingly taking cues from the other thornbills. I assume that the DBF had got lost from its flock and taken up with the Thornbills (there wasn’t any suitable DB Finch habitat within eyesight).