Do ALT’s that become JTE’s still have to work with an ALT?

Say you John Smith American man, starts as an ALT, gets perfect Japanese, pursues all qualifications and become a JTE, and gets hired into a japanese middle school. Do you then still have to work with an ALT?

I don't know if this ever happens, but its a thought?

Edit: it seems so, I would be genuinely interested to know what the dynamic is there between 2 native speakers team teaching.