I understand that. But he practically gives a history of some of the the opposing theories' development and fall from favor, right off the bat. I couldn't get more than a few dozen pages in.
My problem is that I can't find a middle ground between focus on frivolities, and "spends half the time arguing historiography." Your own criticism of Norwich actually seems very much like the latter phenomenon, in that you seem to be criticizing things offstage, i.e. that I can't see and didn't know were relevant. There's middle ground between the two where the layman can actually learn things, but I haven't found it.
Do I just have to study it formally? Is actual work the key? I've never yet found a history book I would reread just because I wanted to, even though I like history and read lots of articles.
Well, the fact that you didn't know that these things were problems in Norwich is kind of the problem. You can't know. Unless you scour the bibliography and track down the texts he cites like a hawk (assuming they have decent English translations, and some of them do not), you don't know what he's really telling you. And you certainly don't know what he isn't telling you. You don't know anything about modern scholarship because he explicitly ignores it (although he makes it clear that that's what he's doing, at least in the three-part series, and only if you read the introduction and pay attention to it), and because, if you are the general reader, you don't know what you don't know. You don't know that there have been massive amounts of work done on the Byzantine economy, the Byzantine military, Byzantine religion, Byzantine politics and ideology, Byzantine literature, and even Byzantine sexuality, all of which makes use of the same sources that Norwich uses but all of which goes far outside them to use sources of every provenance imaginable. All Norwich gives you is a view mostly of what happened to a small group of people in one city, without really explaining much of it, and without pointing out that that is, in fact, what he is doing.
Because you are a reasonably intelligent reader, you see holes in this, and you understand that there are things he isn't telling you, but he gives you no clue as to what these things are. That's the value of historians adding in those bits about arguing with other historians. Feel like something's just a bit off about one historian's argument? Read the work of the people on the other side (conveniently cited in easy reach), and see how they stack up to each other. Feel like something's off about Norwich's argument? Too bad, haha, time for you to do some research.
Unfortunately, using your own brainpower to figure out which historian is the most persuasive
is a fair amount of work. Historians like it this way - at least, the good ones do. It means that you're capable of actually using that brainpower to develop critical thinking skills and question authority, rather than accept unquestioningly any truth that is told to you. Questioning established historical authority is one of the fundamental building blocks of the practice of history. Sometimes it can seem like that means that there's a yawning gap between the kinds of books you read in lower-level undergraduate courses (the high-school-style textbooks that tell you what happened, and very rarely why and how, without making it clear how the author arrived at this interpretation and what the facts are both for and against it) and the books you start reading in upper-level undergrad and graduate classes (the ones with lots of argument in them). Unfortunately, that's...kind of how it is? If history's to have any rigor at all, it's got to be founded on reasoned argument and debate. A historian who is laying out an argument in her book is obviously trying to sell you something. A historian who is not laying out an argument in her book has already sold it to you.
As before, I think you're vastly exaggerating the amount of engagement with the historiography that any reader actually needs for most texts. You're not reading
Metahistory. Halsall spends a bit more time on historiography than some other texts, but the bulk of his pages are dedicated to proving his point by describing the way the Western Empire worked in the fourth century, the way it worked in the fifth century, and by building a narrative to describe how it got from point A to point B. I grant that the last two-thirds of the first chapter are dedicated to some stuff that might be a bit confusing for a first-time reader, but I don't think it's too much to ask to struggle through less than twenty pages of a very basic potted historiography so that he can explain why he is writing the book and why the book is different than all the other books. That seems fairly reasonable for any author to do. Otherwise, hell, why write another book on the fall of the Roman Empire? The tough part comes, I would say, rather later in the book, when he addresses
hospitalitas. It's a historical concept in late antiquity that's pretty awkward because it's complicated - you have to be able to address a tortuously-argued and poorly-sourced Latin legal issue - but also extremely important because the solution to the debate is the foundation for how those barbarians even ended up living inside the Empire anyway. It's almost unavoidable but it makes for very dry reading. Halsall doesn't spend nearly the time that other authors do on the subject (e.g. Walter Goffart) and clearly tries to make it a bit more painless than it could be, but that is still some amount of pain. But, like I said, the bulk of the book is narrative and thematic history about topics that don't really tax (sorry, pun) the reader.
There are easier books about other subjects. There are also
much harder books.
I would say that scholarly history on classical and medieval subjects can be harder because of the source issue. Often, historians do not only disagree on what is happening and what it meant but on
what the primary sources are even saying. That adds extra layers of argumentation on and makes the subject more complicated for the beginner. Usually, with more modern history, historians mostly just disagree on interpretations rather than events or details. There are, of course, subtle signs for the specialist to notice. Two different historians might write two different histories of the Thirty Years' War with two different interpretations of what it was about, or why it mattered, or what have you, and they will focus on different events in that history in order to prove their point, perhaps omitting inconveniences or offering explanations of those inconveniences that do not pass muster with the other historian. There is no kind of history where the reader will be totally free of debate and argumentation in academic history.
History is complicated. It can be pretty tough to wrap your head around it. And it's a field where a lot of the books geared toward the moderately interested layman are badly and fundamentally outdated, deeply misleading, or outright lies. You don't need to be a top-flight philosopher to get through an academic history book, but you do need at least a little bit of fortitude, and you will be doing yourself a massive disservice if you simply want to be told what is the right answer.