It is possible, you need 3 separate sources of damage on this particular map and Karax can pull that off:
Towers on the defending (wave) side.
Units on an attacking side.
Topbar on another attacking side.
As only half the units are your polarity you technically only need half supply alive to be “active”, you can retreat as soon as you killed all units your polarity at a camp / most of them.
Of course, your ally has to at the very least synch with you on the defending side (topbar doesnt need him since your observer should be out of range of enemies)
Ideally youd have two unit groups and so would your ally and theyd walk together and in parallel, but yea… that will only happen when playing with vets.