This is it, in a nutshell.
A foreign coach makes little sense when so many of the players have such poor command of English.
A similar (but reverse situation) occurred when a few foreign coaches came to the Premier League with poor command of English — it occasionally worked for a bit, but when the going got tough, it was dire. The foreign coaches in the PL now can speak and communicate with the players.
However, once you had appointed the person, agreed the terms of engagement etc then you have to give the person a decent period of time, stick to the contract etc.
Otherwise, you appear dishonest, deceitful and untrustworthy— all of which may well be true.