Christina would be a new age final girl.
Beautiful, capable, smart, strong, and sexy while still being moral, sympathetic, and likeable. Queen of Slasher Films
Britney would be her lovably ditzy best friend who has a nude scene and dies in some OTT way
Madonna would be the killer with her motive being that these new girls are stealing her spotlight
The OP basically nailed Mariah
Taylor would be the fakeout final girl. Uver try-hard to the point of eye-rolling virginal goodie good who dies in the last act to establish "anyone can die" even tho we all know Legend X is the true survivor.