There are some pizza operators who choose to put the pepperoni under the cheese. Buddy's in the Metro Detroit area does that. See, for example, page two of its menu at http://www.buddyspizza.com/documents/BuddysMenu.pdf.
On the matter of hard facts on pizza making, over the years I have spent an enormous amount of time on the Internet trying to find hard information on pizza making and I don't believe that there is any place that has more hard facts on pizza making than this forum. However, there is a lot of information on the bread side that applies to pizza making also. You can go back several years and read E. J. Pyler's seminal work on baking (https://www.amazon.com/dp/0982023901/?tag=pmak-20
) and you can read Professor Raymond Calvel's The Taste of Bread
) or you can simply do a Google Books search where you will find all kinds of highly technical (and usually very expensive) books on the science of baking. Another useful resource is the writings of Didier Rosada on preferments, at http://web.archive.org/web/20040814193817/cafemeetingplace.com/archives/food3_apr2004.htm
and at http://web.archive.org/web/20050829015510/www.cafemeetingplace.com/archives/food4_dec2004.htm.
On this forum, one useful area we have found on the science of baking is the theartisan.net website at http://www.theartisan.net/TheArtisanMain.htm.
At a more basic level, and mainly for the newer members of the forum, the forum has a Pizza Glossary at http://www.pizzamaking.com/pizza_glossary.html.
You might also do an Internet search for articles written by Tom Lehmann, an acknowledged pizza expert at the American Institute of Baking. He is one of the very few in the industry who writes regularly on the subject of pizza making, including the technical aspects of pizza making. You can also read his posts (including in the archives) at the PMQ Think Tank forum at http://thinktank.pmq.com/viewforum.php?f=6.
I have referenced most of Tom's articles on this forum. If you use the keywords "Lehmann article" (with quotes if you use the Google Custom search feature and without quotes if you use the Advanced search feature), you should be able to find links to most of his articles.
The above said, there is hardly a technical area of pizza making that has not been addressed or written about on this forum. And, in my opinion, they are not fluff pieces. If you use the Advanced search feature at http://www.pizzamaking.com/forum/index.php?action=search;advanced
or the Google Custom search feature that is accessible at the bottom of the main index page of the forum, you should be able to find posts on pretty much anything, provided you are willing to spend the time scanning and reading the posts. As an example, if you use Maillard as a keyword search term in the Advanced search engine, you will get three pages of hits. If you use the Google Custom search engine, you will get two pages of hits. You might also do a search of posts that originated with Bakingbusiness.com. If you use that term as a keyword in the search engines, you should find several articles of a technical nature, many of which apply to pizza making as well as baking in general.