As you suggest here, it is a great way to begin thinking about theory, practice, and consequences. We should discuss this. Most of the time I am at a loss for an explanation of my decisions. Usually I am employing a method I learned from my professors, or reacting against what I have been asked to do in the past. Because of this, I liked Hillock's discussion of frame experiments and reflective practice.
Theory creates practice, but practice revises and informs theory.
We can know countless writing theories, but if their implementation fails to reach our students, we must be able to invent new strategies to try. They just can't write. Reflective practice allows teachers the freedom to move beyond what has always been done in the past. Saying that, I do think it is important to have a knowledge of composition theories and how they affect and develop my teaching practices. If we are capable of doing this, the teacher becomes free to be a learner as well.