He's the only one who can wield the sword, and is meant to be a warrior. This kid was VERY out of shape.
Maybe a personal trainer six months prior to shooting could have whipped him into shape.
They picked this kid to show that anyone can be a hero so making him relatable to the average joe.
shareI liked the way they had an "average" kind of kid in the role, and it helped with the whole bullying aspect and how they ended up together.
I thought this movie was a lot of fun in the first half as things got setup. The second half fell a bit once that was done.