Referring To God As Allah Miyan
میاں means owner, king too. Intrinsically there is no problem in it. If I loosely translate, Allah Miyan it will mean the Allah the ruler.
In the Quran, Allah tells that all good names are His, call Him with any good name. So, any name which a people find good to name Allah, is fine. So much so, the name “Allah” is too given by the Arab to God and Allah adopted it in the Quran. It is not the just an individual, but the people collectively adopt a word for that use and other just follow as they follow other words for other use in a language.