Applebee - Glued English

Appleebee talks about the tendency of English to come "unglued" into parts (p. 59) and earlier (p.32) cites Clapp's recommendations for specific English tasks that students should learn to do (prepare speeches, read legal documents, etc.). I understand how English can be taught holistically and authentically without taking it apart, but how much should we try to fit into a class? Should we leave the preparation of speeches to speech teachers? Should there even be a speech class? I know I learned more about speaking in other classes than I did in my speech class.
Speech is easy to fit into English without separating it from the whole. But what about the more specific tasks like reading legal documents. This is, I would say, an important ability. But it wouldn't necessarily fit neatly into the conversation curriculum Applebee discusses. So I started thinking, is teaching kids how to read by using this type of curriculum enough? If we can teach them to think and be metacognitive without necessarily making an isolated lesson of metacognition can they take what they learned tacitly by doing and use it (tacitly) when reading a legal document?
I became a better learner when I learned more about teaching . . .