Please explain how 'retargeting' with auto attacking works?

Tiltowait

I tried this because of the banner tip that the game had.
Well as far as I can tell it doesn't work. If you select a target, your group will instead randomly attack other opponents.
For example my team is facing a Bariss/Lumi team. Since she can heal the entire team over 10k each a pop and my best crit is only 5k sounds like a good idea to target her. Try it and each one of my team dropped their largest attack...one each on every other target. When they were done for the first round each opponent was at 60% health...which was instantly healed.

One match just out of perversity I kept retargeting one foe and at best I would have 3 attackers hit her, dropping her to one red bubble of health...then they completely ignored that target again targeting random foes but never concentrating on one until her heal reset its cooldown and she fully healed herself and her teammates.
Rinse, repeat.

Is there a way to retarget and have your team actually follow it?

Cheers and thanks!