The Basic Idea: During her training with the waif, Arya is told to name her brothers. The injuries she sustains after each name correlate directly to the grave injuries inflicted on the other Starks.
The Problem: It's kind of insane to boil Robb Stark's injuries down to a stab wound in his left side. It's completely undermining the fact that he takes like, five arrows to chest first. Furthermore, if you look really close at Arya's injuries in this scene, the waif actually thwacks her on the left shoulder. This is coincidence at best. Rickon will not likely sustain a leg injury.