Board Thread:Questions and Answers/@comment-37118673-20181006194150/@comment-1327106-20181006202628

It likely was a trade-off for efficiency/flexibility.

Generally speaking, you're not going to be shooting someone directly behind you because your body positioning is going suck. In real life, if someone is behind you and you need to shoot them you want to turn around. You're not going to keep facing forward, lean backwards a bit, and then point your gun over your shoulder. Your aim is gonna be terrible.

But that's what the Survey Corps would have to do, because they would have forward momentum with their grappling lines. Chances are most of their shots would miss even if their gear allowed them to shoot separate from their direction. Someone like Levi and Mikasa might be able to spin on their lines so they're upside down and do shots behind them that way, but that's not going to be your average soldier. Yes, being able to shoot behind would be better than nothing, but it would be a marginal advantage and first opportunity you're going to change direction anyway.

On the other hand, it's very likely that when you have a target you want to shoot, they're going to be in front of you, which is the direction you want to go anyway, so it's very efficient to be able to shoot and move in the same direction, even in the same motion. Raise arm up to shoot weapon. Raise arm a little further to shoot grappling line. It asks very little from a soldier who is already under the pressure of combat.

With traditional maneuvering gear, aiming the grappling lines and attacking are two separate actions (they aim with their hips, attack with the arms). With the anti-personnel gear, they can do it in one, and people are probably better at aiming their grappling lines with their hands than their hips, which would allow for more accuracy.

There's also a lot more flexibility. Traditional maneuvering gear can only go in the direction the soldier can face their hips, but anti-personnel gear will allow a soldier to grappling in any direction they can point their arm. If you're standing on the ground, someone with anti-personnel gear can easily grapple straight above them. They just point their arm up and shoot. That's difficult with traditional maneuvering gear, because it faces forward. A soldier would have to lean extremely far back, practically falling over, to do the same thing.