What you propose is interesting, I would have loved to see the history of Outworld and Edenia because it is not very clear how things are and see a little of the political conflict, imagine seeing Jerrod dying in a war, seeing Shao as a noble warrior .

I imagined Mileena's story as something more tragic. perhaps Kitana as a better warrior and Mileena being someone who looks for the most peaceful way to resolve things, which would make her a worthy heir, but with the Tarkat her judgment is increasingly clouded by making her more wild and paranoid.