Party: Isolde (R10 / P1), Six (R10 / P0), Voyager (R10 / P0), Vila (R10 / P0)
Decided to have a crack at this without the Doctor.
Isolde: This fight is a lot easier with a decent Mass Attack DPS. It's very hard to target both enemies with single target attackers because of their shared passive, their Ults also make it really annoying to coordinate your attacks (the Stun is obvious, but other Ult also inflicts Weakness stacks). Marcus is technically good too but I wanted to try a different DPS for this run so I went with Isolde.
Six: I went and re-did 6-1, just because I wanted to see how useful his Buff / cleanse would be for this fight. Seems like he can't remove everything, which is pretty annoying, though his debuff still helps a lot.
Vila: After trying many healers, I had to go with her. Just because she still supports even if she does get stunned (if she's in Rusalka status, her free Eureka and Moxie up still works. She'll also still activate her passive heal at the end of her stunned turn).
Voyager: She's really only here for the Sturdiness stacks on her Counter. If I had Medicine Pocket at R10, I probably would have run MP + a second, non-Vila healer.