Hermit Yoda’s Mastery

I don't think it's as clear anymore—I think it used to say in-game somewhere—but each character's mastery is based on that character's archetype. There are 12 archetypes: 4 classes x 3 primary attributes. Hermit Yoda falls into the Tactics Support archetype, whose mastery increases damage, accuracy, and crit avoidance, as you noted. 

Obviously, two of those don't do much for Hoda. But it makes sense for other Tactics Support characters, like R2-D2, Admiral Piett, and Bastila Shan (both of them). 

So the real weird part is that CG made Hoda a Tactics Support to begin with. I keep forgetting that he's not a Healer, and Tactics Healer mastery would have been more useful for him (health, resistance, crit avoidance).