I usually use a full interrupt lifesteal team which auto clears first map. Then have 2 different teams for clearing second.
For the first map: Guy, neiji, iruka as bases- then throw in solid dps.
If you lose people just retreat and you wont lose them for survival- retry the fight with other combos and try not to lose any ninjas.
Does this work without Irukas absurd shield ? Because life steal on its own won't save them from strong lightning teams with multiple taijitsu attacks. I usually clear most of first map with empress because you get a shield without having to shell out for Iruka .