He serves a vital role in the story, especially Mats', and while he is not Gaidal Cain or a t'averen or what have you, I'd like to think that every soul is important to the Pattern, which is why Rands' massive balefiring of a small number of people (relatively speaking) nearly caused the entire Pattern to be unraveled so easily. A soul is an important, permanent element, and in that way everyone possessed of one serves a greater purpose than the one they know of or understand.