We will eventually get danzo in the shops, kk gaara in the plot instances and if you are in deep need of another barrier ninja you can buy it with coupons when appears in event, but currently you got chojuro, mifune and bee sst that are the only useful ninjas from kage that you need to get good synergies with gnw treasure. The game told you to go in gnw, never go against what the game tells you because will cost you a lot.