Also, I understand placing Susie’s death first because one of Withered Chica’s lines in UCN in “I was the first, I have seen everything” but I’m pretty sure that just refers to the main 5 killings (Susie, Jeremy, Gabriel, Fritz, Cassidy) since in the UCN interlude cutscenes it heavily implies William killed the MCI very close together (highschool Toy Chica says how she’ll seduce each of her crushes, which lines up with the MCI, and still allows for Susie to be first and Cassidy last). Also, the FNaF 6 Lorekeeper ending shows 6 gravestones, with the names of the 5 MCI (sans Cassidy, whose gravestone has crumbled due to being TOYSNHK) in the foreground, with the sixth gravestone being on a hill in the background, Charlotte’s, showing her death is separate from the rest of the MCI, which wouldn’t be the case if Susie’s death was first