It's not 100%, since i personally know person that got ao, oro kt and ao again. However chances of that must be really low, since its I've seen that it happened to. Pretty much every video (and group pull, including me) that reached 180 scrolls got all 3 rares.

If some1 wants sage naruto but hasnt put any scrolls there, its better to piece him from events than invest scrolls. Each event (f2p way) can grant u ~15 frags, it doesnt take very long.