1)perhaps being a rebbe is not actually the BEST kind of job for this person & something in this chapter but a different job is better for him i.e. being a private tutor or a sub which is less pressure on him & a way lots of people start before becoming full time rabbeim. just like lots of jobs first you work for someone to get experience in the business & then you go on your own….
2)it takes a lot of love for torah & love for children to be a successful rebbe. if the person can’t give his entire self to helping each child to stay on track with the rest of the class then he is not ready to be a rebbe.
HATZLACHA