the Reformation's "minimum kit"

I recently began reading Diarmaid MacCulloch’s The Reformation, which by all accounts is a magisterial history. And about a hundred pages in, it sure looks like it. But here’s a curiosity: MacCulloch announces in his introduction that he’s going to add, in an appendix, a few central documents that will enable his readers to understand what these people — the objects of his historical scrutiny — cared about, argued about, and fought about. And what are those documents? The Augsburg Confession, perhaps? Documents from the Council of Trent? No: he means the Ten Commandments, the Lord’s Prayer, the Ave Maria, the the Apostles’ and Nicene creeds.

MacCulloch calls this “the minimum kit that those caught up in the Reformation would have had at their disposal.” Fair enough, though I suspect that almost everyone’s “kit” was rather larger, though in varying ways. But I can't help wondering what someone would make of this very large book (750 pages in quite small print) who didn't already have a good grasp of those documents. Would someone to whom the Lord’s Prayer is unknown even pick up this book? Would someone who doesn't know the Creeds be able to make sense of the narrative, of the theological arguments that are a significant (though not the largest) part of it?

I understand that writers today cannot assume a level of cultural literacy that was common in the past; and I know from experience that trade publishers are constantly aware of this problem. But the addition of this “kit” to this particular book, which would seem to demand a certain level of historical knowledge from anyone who might happen to pick it up, seems odd. I wonder if the appendix was MacCulloch’s idea or his editors’.