So I went down the rabbit hole of these forums and the SotM BGG forums and ended up reading a bunch of threads from 3-4 years ago, and came across this comment made by Paul.
You can find the original comment and thread here.
Limited applies to the entire table. Expect this rule to be relevant at some point in the future :)
Now it is possible this idea ended up on the cutting room floor, but with the new Villains turned heroes and possibility of Heroes becoming Scions, Maybe this is still going to happen.
Do we have any word that it won't?
This already can happen thanks to Guise's Lemme See That. This may be what he was refering to.
That is true, I was thinking by deck, not play area.