I believe it was a mistake for Blizz to move away from the old valor system. It used to be that each new tier of content brought with it a new currency which could be used to buy normal-raid gear. Raids would drop tokens which allowed such gear to be upgraded. The system took a lot of RNG out of the equation and still kept 5-mans relevant since completing them awarded currency. The end of each tier saw Valor converted to Justice and the cycle repeated.
In legion it would work just as well. Make all normal-raid gear (possibly exclude tier-set) purchasable for between 30 and 60 tokens. Heroic 5-mans award 2 at the end boss. Mythic+ award 3 plus 1 extra per "+" level. LFR awards 3.