I think what you are describing is what used to be called a whole language approach to teaching. I am most familiar with this concept as used in the elementary schools. The strategy was to use a theme, of sorts, in which every subject was immersed in the theme. I seems that with adequate training every subject teacher could be part of the army of reading and math teachers by including proven reading/writing and math strategies into the lessons in science, social studies, computer science, etc. This was the focus of my district where every teacher was expected to teach reading and writing within the curriculum area. Those who took advantage of the "reading specialist" to learn effective strategies contributed to the overall goal.