I haven't beaten it yet but have got very close with a double dodge lead - either Old Ben, Lumi or Ahsoka, one from ally and one your own lead.
Both my Ahsoka and Lumi are still only g8 which is probably why I have lost - but I have got them down to only 1-2 toons left in the final round.
Also, the enemies you face are highly variable - I have had between 3-5 enemies in round 2 for example, and they vary between the two types of aoe. So you have to rely on luck in terms of the enemies you face as well as during the actual battle.