I guess I'll get to see the quality of their teacher training then!
It's not about teaching in the sense of normal classroom teaching, its a blend of how to brief and debrief practical lessons. I went into the FI on the back of a Cert Ed and teaching/examining professional diving. Being able to create presentations and stand up and give them helped but there was no one part of the FI course that I could say could be omitted due to prior qualification.