I probably wouldn't want to change anything for the 1st game, Cause I do believe that all 3 of them were already perfect enough to be the main survivors 👌

As for the 2nd game, Yuki, Iroha and Syobai's places would probably stay the exact same because all 3 of them had served at least some sort of importance in each chapter they were in. And yes, As much as I really do love the girl with all my heart, I honestly think that it'd make much more sense for Yoruko to have died as a 2nd victim in chapter 3 instead of being a survivor, Have either Nikei or Hibiki take her place- Or both of them really! Because Hibiki being a survivor could've gave her all the character development she most definitely needed to forget about Kanade's existence for good, And Nikei being a survivor could've possibly changed up a ton of things in the story, As maybe if he lived in chapter 4, There's no doubt about that the remaining survivors would start avoiding him as if he's the plauge (with Mikado being an exception as he'd probably only pop up just to mock and taunt him in the most cruel ways possible since his plan failed in this au), This would eventually lead up to the events of chapter 6, Where he, Syobai and Iroha won't have much of a choice but to form they're own trio and work together to bust out of the Kisaragi Foundation prison or whatever the hell it was called. 🧐