Hi Iam2,
The "instuctor" training , I believe is by invitation. The "guide" program is just a sign up to take the course, hence, I would guesstimate a large number of guides down the road. I think the position of instructor or teacher, however it will be called, is and will be a more accomplished position.
Being invited to be an instuctor, is probably one in the same as becoming a private student. -g