"All teachers" does not, of course, include special sducation teachers.
Most special ed teachers are licensed as both general education teachers AND special education teachers. If credentials mean anything, you might say special ed teachers are twice as smart, or at least twice as educated, as regular ed teachers.
Most special ed teachers seem to have master's degrees as well, at least where I work.
But credentials don't mean anything. Despite all those fancy framed pieces of paper, in the end we're only special ed teachers.
We're being "asked" to fill in as substitutes on 15 April while the real teachers are away.