Not Necessarily God’s Will
The commentary on Judges 11:6 in the Apologetics Study Bible states that is wasn’t necessarily God’s will for Jephthah to be their leader but God went along with it.
This reminded me of a truth I learned many years ago: God’s will isn’t always done; some things he just allows. This means we shouldn’t think that just because someone holds a certain position that it is God’s will for them to be there. And just because God allows something doesn’t mean his blessings, or at least full blessings, are on that situation.
Living in an imperfect world, we will always have to deal with people operating outside of God’s perfect will. Most often they are not the only ones to suffer the consequences either. It could be entire families, churches, businesses, or nations.