I feel like the clan system should take a page out of Shogun 2, and have every clan have a unique unit, an upgraded/specialized unit like a flame-arrow archer, a female crossbow sharpshooter (that can be directly recruited) or super-knight to give all that clans a distinct feel, and a reason to join them, whilst remaining within a single faction. An even cooler step would be to allow you to start your own clan, and allow you to create your own unique unit, which not only allows to increase your clan identity, but give the system a new layer of strategy. (ex. Do I want a super-elite unit? Or do I want a highly competent militia force that can be quickly and cheaply raised?)