with due respect to all individuals here, i think the teacher should master the language, i.e, the medium of teaching.

so if you are teaching English language: you definitely need to be a native speaker of English

If you are teaching Math, Science, history, etc, in English, you definitely need to be a native speaker of English or close to that level.

If you are teaching Math, Science, history, etc, in Arabic, you definitely need to be a native speaker of Arabic or close to that level.

and if you are teaching Arabic language: you definitely need to be a native speaker of Arabic

and if you are teaching Hindi language: you definitely need to be a native speaker of Hindi

if you do not master the medium of teaching then we have a problem

i think this is common sense, am i wrong?