User blog comment:Dave55811/Chapter 58 is out now./@comment-10733658-20140610053840/@comment-5310175-20140610075541

I think you're right about Jean's role in this arc, he's trying to keep his humanity safe but at the same time, he wants to help without throwing away his humanity, like Levi and Mikasa already did, and Armin is doing. His role is like the being against being a murder, but at the same time he has to be it without feeling regrets, and that's why he's having a hard time. And that adds some interesting facts about who will be the next commander in the future, Armin or Jean.

And about the Sasha and Connie, both are there, mostly because they were almost main characters, during the fight against titans. Both had an important role until the fight against Reiner and Bertholdt. But their presence in this kinda of fight (against humans), is mostly because the fandom likes them, so they are supportive characters, if you come to think their presence is irrelevant in this arc and well they have to kill humans if they want to help, and i really see hard that Connie and Sasha could do that, if Jean can not do it, I highly doubt that Sasha and Connie could. Isayama has them there for the future arcs. So he will not kill them, but it will not giving them an special treatment like he's doing with Jean.