The four screens are needed for people who cannot see the big screen. If you are far up enough in the North, or under overhangs you cannot see the big screen. The screens are needed.
That's why he said make another big screen in South Stadium.
And even if that is still there if you are under the overhang you still won't be able to see it. I like the idea of moving the screens, though I don't know how realistic that would be. Don't get me wrong, I love the inscriptions. Now that I think about that, aren't the inscriptions facing out from the playing field?