I don't see anything wrong with it. Probably the last thing we should be complaining about is that there's too much documentation, unless the documentation is factually incorrect or if it's an outright duplication of something that already exists. Better too much than too little. Their code looks OK to me, from my brief glance.
Note: they do link to perlfaq and http://faq.perl.org/, on the links page here. (I am going to recommend to them that they link to the others.)
I think that people learn in different ways, and even a slightly different approach to something might be enough to help a person understand better.