First off, the name - Argent's Alchemical ally is Entrancingly Arrayed Sentinel, or just Array for short. I don't know what her regular job is (that is one of the things I'm hoping will shake out when her caste is decided), but working with Argent isn't her primary task, she's not a worker at the Howling Wolf (she was in her first incarnation, but that's an Age ago).
Array's role in the group is one part intelligence gathering apparatus, one part combat-bot. One of her defining Charms is her Optical Shroud, which she's upgraded with as many submodules as she can. I'm considering giving her Thousand Gear Wounds Style MA, but the more I've looked at it, and at the Charm, it doesn't really seem to mesh with my thoughts of her - I might just give her a klave and let that be it.