Who is Aaron from Deal Breaker and what is their importance?

Aaron and Myron Bolitar formerly attended high school together and dislike each other immensely. Aaron is described as an extremely large man, who is employed as a paid thug for Roy O'Connor and the Ache brothers, and although, Aaron fancies himself a man of style and good fashion sense.... he is anything but. Aaron wears suits without shirts and doesn't wear socks. The narrator does points out, however, that, "Aaron was the definition of 'super smooth' - just ask him, he'd tell you".