This stuff on the OS contradicts itself, as usual. Here is the descrition of them per the OS:
Elegance and deadliness --- these are the hallmarks of the crimson-clad Royal Guard that accompanied the galaxy's sovereign at all times. While the guards can trace their origins to the cerulean-clad Senate Guards of the Republic, Palpatine crafted an order of protectors that stood apart from the rest of his forces.
Only the most promising of the Imperial ranks were selected for Royal Guard duty, based on stringent requirements of size, strength, intelligence, and loyalty. A Royal Guard was completely covered in flowing red robes and a sleek, featureless scarlet mask obscures their faces.
And again per Pabs:
From 8/25/04
Will the Royal Guards continue to just standabout looking cool or will they finally get a chance to prove their worth?
They don't kick any butt. Quite the opposite, actually
So are they the best of the best or pretty crappy? Seems like even the OS doesnt have a clue. But all of this, while fascinating, is kinda not the point.
Why are these guards not dead in the shots we see in the trailer? Thats what I cant figure out......