On a recent trip into the Fissure of Woe with some guild mates, I was placed in charge of the Tower of Strength. When killing the Shadow Lord from inside, I noticed that the Shadow Mesmers attacking me appeared to have White Mantle symbols emblazoned upon the back of their necks. Should this lead me to believe that all members of the Shadow Army are merely the lost, tormented souls of the White Mantle, who we so ruthlessly slay on a daily basis?
Clearly adding the symbol to these creatures was a conscious design choice, rather than mere coincidence, so what can we take from this? Any theories on the
true origin of the Shadow Army?

The White Mantle banner, as displayed on Guild Wars Wiki.

The White Mantle symbol, as displayed on the clothing of Shadow Mesmers.