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Three men we take to be Lannister men-at-arms or knights, given the red. Interestingly, these garments are quite different from what we see elsewhere among men of higher rank. This variation may be something to mark out westermen. It is a very early Medieval look, in which very long tunics and robes were de rigeur. Their swords are particularly notable here for their size: they are war swords, or hand-and-a-half swords, rather than mere arming swords. One also notes that the hilt seems a little bent at the end, an interesting detail.
At a guess, this is from the original pilot. We would not be surprised if the costuming has changed somewhat for the reshoots.