It does seem a bit strange at first glance! Maybe he thought understanding the rules from a referee's perspective would give him an edge on the pitch or help him avoid unnecessary bookings. Whether it actually helped Arsenal is another question.
In my field, working as an elder carer, understanding the regulations and best practices behind care can definitely make you better at your job, so perhaps the same logic applied here. Sometimes learning the "other side" gives you a different perspective, even if it looks unusual from the outside.
I quite like how his plan is unashamedly to play dogshit football and just try and Moyes his way to wins. He really doesn't care what anyone thinks and believes this is the way to win things. Let's see.