I saw this answer by griewei here: https://apple.stackexchange.com/a/124479/81640
Unfortunately I don't have enough rep to comment.
What I would like to do is something similar e.g. - one latest greatest Mac Book Pro Retina - 2x Thunderbolt Displays - 1 Apple Cinema Display via HDMI adapter etc.
@griewei said he was doing this and it was working; does anyone know if the Apple Cinema display is scaled at 2560 x 1440 in this configuration?
I know it was not possible in Mountain Lion but I heard it was possible in Mavericks