Apologies, but I do work at a tabloid

So Nicole Kidman and Jennifer Lopez have been cast in "American Darlings" a movie about women overcoming men and race and class through the power of song. In the 1930's. At nightclubs. Where, they will both, apparently, be "singing."
Why does this pairing strike everyone- by which I mean me- as bizarre? It's not like they're Jennifer Aniston and Brad Pitt who, if you can think back to a time before they were anointed, initially seemed like an odd pairing because they came from different leagues: untouchable movie star and cozy TV actress.
Lopez and Kidman are both ridiculously famous, in a similar fashionista, rich, buzzy way, but apparently there are divisions within that category too. Such as Kidman has lots of credibility and respect as an actress and Lopez has lots of credibility and respect as a person capable of making headlines. Or, in other words, J-Lo be trashy.
Mr. Affleck seems to think America was against him and The Lopez because of issues of "race and class," and while I tend to think America turned against them because of their expansive fame-whoring, I wonder if that's part of what seems weird about Kidman and Lopez. Kidman, who must have first dibs on every script in the world right now and has weathered a divorce that most people kind of think was a marriage of convenience, is seen as a pristine, scandal free, beautiful, uber-talented lady, but Lopez is the fiery, sexy, ambitious, scandal maven, with an insane will-to-power.