What does Judges 20:27 mean?

Eleven of twelve tribes of Israel have amassed near Gibeah to purge evil from their land (Judges 20:12–19). Their efforts have not gone well, so far. In two battles, more attacking soldiers were killed than the defending tribe, Benjamin, had when the conflict began (Judges 20:20–25). In response, Israel has taken their entire contingent to Bethel, nearby, to fervently seek God's will. They have spent the day weeping and appealing to the Lord, fasting until nightfall, and making sacrifices to Him (Judges 20:26).

Here, the text explains why this supplication happens in Bethel, rather than Shiloh, which was previously described as Israel's center of worship (Judges 18:31). For reasons unknown, the ark of the covenant of God (Deuteronomy 10:8; Joshua 4:18) had been brought to Bethel. The ark of the covenant of God was a box covered inside and out with gold. The Lord told Moses to build the ark according to very precise specifications. God said He would meet with Moses at the ark to give Israel His covenant law. The ark was to be kept in the holiest part of the tabernacle and was said to contain God's presence and could only be moved in accordance with God's specific commands (Exodus 25:10–22).

Scholars speculate the ark was taken there to help gain God's favor and power in defeating the Benjaminites. That clearly has not worked. The people find themselves asking, again, if they should even be attacking their brothers in the tribe of Benjamin at all. If this is what God wants, why have so many of their soldiers been killed in failed attacks?