As a student, I am well aware of the need for educators to know how to teach
to be effective.  However, I would agree that teaching ability should follow
knowledge.  Learning the subject to be taught is the more difficult part,
and as a student I have learned from the effective and not-so-effective
methods of my teachers.  I believe that there always will remain those who
are quite brilliant academically, but will never be able to successfully
convey this knowledge to the students.  This is why volunteering,
internships, and teaching experience is essential for educators, to give the
student an accurate portrayal of her/his teaching capabilities.  After
learning the material and some teaching experience, decide whether one
should teach and then pursue learning how to teach effectively.