Your analysis makes sense as to the use(lessness) of the Aiel to date, but their point is to come. The truth of the travelling people and the way of the leaf settling in Seanchan lands, crossed with Aviendha's coming epiphany in Rhuidean and the fundamental dishonesty you illustrated in the wise ones and chiefs are all instrumental in forming a mind set that RJ wished Rand to have at some critical moment, propably the climactic scene in the entire series, where Rand will have to decide between representation and being.