Since the look of Klingons, in general, is well established, they would be the same in the Alternate Reality as the Prime Reality.
Same goes for the Romulans, yet Nero and his gang don't exactly look like those seen in TOS or TNG.
They pretty much look like bald, working-class vulcans to me. Oh, and they have tattoos.
Since we never saw working class Romulan oil rig workers prior to this, there was nothing established to say that they did not exist in the Empire.
Fundamentally, they were tweaked TOS Romulans (Humans with Volcan-like features, really).
Well within previously established possibilities.