This is a dysfunctional relationship and logic and reason are of no avail, at least not from amateurs and well wishers. Professional intervention by a trained psychologist is their only hope. Just talking scripture isn't going to do it. They need to be reached on an emotional level, which requires a professional road map.
Good point. Even if the elders are merciful, caring men, they are not trained to handle the issues that come with these type relationships. Best friends can be caring and merciful, but still not be able to help. What makes an untrained elder think he can help them solve their problems by reading some scriptures?
Then there's the uncaring, arrogant elders who make matters worse by laying blame on the abused wife or accusing one or both of not living up to Bible principles and that's why they have problems. For an elder to use the scripture about be obedient to a cruel master when speaking to an abused wife is unexcusable. If she decides to stay with an abusive husband based partly on what that elder told her, he would have to share in the guilt of any injury or death incurred later.
I was never an elder, but I have always maintained this attitude about abusive husbands: If he ever physically acosts you, it's time to leave. You are no longer safe, he no longer is in control of himself. I know that if I was an elder and uttered those words that I probably wouldn't have been an elder for very long.