A 13 week program is bullshit...how can you possibly progress for that long?!? Unless youre starting at like 2lbs and working up by 2lbs a workout...what kind of stimulus is that? not a whole fuckin lot IMO.
Just so I have something positive to say....
Major Body parts listed are: legs, back, arms
& chest
(ie. I read that as 3 things, legs, back , arms and chest. Arms and chest being one of the Major parts) So IMO arms are not being called a major muscle group