>>720759678
This is pretty much my take, Susie was chosen because will no one ask questions if a troubled teenager from a bad background were to just... go missing one day.
The conspiracy is deliberately using the prophecy by changing the actors. Fate is probably a constant but as long as the outlines are followed the exact circumstances are allowed to be ambiguous. Tenna is supposed to be cut down, but that doesn't mean he has to die. Likewise the exact heroes can be changed, assuming they fufill the same role. I would go even more schizo and start rambling that its possible Kris was never meant to be the cage either but thats a bit off-topic. If you want a TL;DR, look at the cage prophecy graphic and realize the hands are purposely non-human and four fingered.