My PvP set is entirely different and covers me fully from head to toe. But...I've seen LOTS of people in similar gear sets. The only thing that remains unique about my PvP set is the fact that I wear my guild tabard with it.
I fail to see how either set covering me or showing me off makes a difference to how I play the game. It's not reality, the appearance of my armor doesn't add or detract how much it actually protects my characters. The stats stay the same regardless of what it looks like.