One of the things that made the text for World Wide Wrestling effective for me is that Nathan was completely unafraid to simply repeat things. Where something is relevant, he explains it, just about every time it comes up. This makes it longer, yes, but it means that it is a pretty good teaching text (because you can easily see what is repeated and skim past to the new), and a very good reference text (because if you look up something with the TOC, related concepts will almost always be explained nearby).