Which one is better, English taugh by Native Speaker or English Teacher

I think english teacher better than native speakers, it can be viewed in terms of English teacher education is better because before becoming a teacher through several stages such as KKL, KKN, well as studying grammar, pronounciation, and vocabulary are more like before becoming a teacher. besides English teachers must complete to determine the proper education or not being a teacher, while they are not native speakers should be able to master the grammar, vocabulary, etc. The most important could be speaking. for example, a seller of newspapers every day to read so that they can speak English but have not mastered the grammar and he could become native speakers, whereas English teachers mastered all about the English language.