Based on my analysis of the scouts:
http://www.ootpdevelopments.com/boar...d.php?t=145839
I believe there is a glitch for getting the ratings on IF Arm and OF Arm since there is basically zero variability. Speed also has basically zero variability, but that makes sense since you could get a rating based on timing them in a sprint (so there is no opinion needed by the scout).
Unless there is some test in real life I'm not aware of for measuring IF Arm and OF Arm abilities that would cause this, I think this is a bug.