Tenuous at best in many school systems where it's typically not teachers that apply corporal punishment but headmasters.

The notion that people train to be teachers followed by spending ~10 years in the system holding out for the chance to be a headmaster just so that they can beat people is a stretch.

Bound to be one or two, but there are surely better paths for a sadist - prison guard, et al.

Give this a watch - https://www.imdb.com/title/tt2070649/