Here’s the failsafe for the Airstrip run: Assassin Bomber Boy. Buff him up however you’d like, but he really shines when the Field Marshal kills him... His passive (explode or something) instantly kills the Marshal. So, buff him enough that he survives the first round (so that that irritating golden health/regen buff - whatever it’s called wears off), and then watch the AI kill itself. Win.
Completed the whole thing with Soldier Ed, Ass BB in the first slot, Gunner Rockets in the second slot, and Gunner Undead Soldier in the third slot, 100% on auto, no deaths. No fancy talismen other than level 30 cosmics to boost the dmg/passive punch. I’m sure there are better teams, but for newer players, this is very safe.