Hello Ivo,
Perhaps it is too late, but the pose is not good for this figure. The right shoulder must be raised for this pose. Since he is wearing the cuirass, then the cuirass must be raised at the right shoulder - and tilted down at the left. Otherwise it looks like he has a dislocated shoulder - very painful and unrealistic! This pose is impossible without raising the shoulder along with the arm.
It would only be a case of adding a wedge at the figure's waist to raise the shoulder.
I hope this helps!
Cheers!!
Mike Good