Contradiction with Malachi 3:6
This verse speaks of God's unchanging nature, which may contrast with the fickle outcome and uncertainties of battle depicted in Judges 20:22.
Malachi 3:6: For I [am] the LORD, I change not; therefore ye sons of Jacob are not consumed.
Contradiction with Matthew 5:9
Advocates for peacemaking, which contradicts the theme of going to battle as seen in Judges 20:22.
Matthew 5:9: Blessed [are] the peacemakers: for they shall be called the children of God.
Contradiction with Exodus 14:14
Emphasizes God fighting for His people, which contrasts with the Israelites encouraging themselves to fight.
Exodus 14:14: The LORD shall fight for you, and ye shall hold your peace.
Contradiction with Romans 12:19
Urges not to seek vengeance but leave it to God, contrasting with the Israelites' actions in battle.
Romans 12:19: Dearly beloved, avenge not yourselves, but [rather] give place unto wrath: for it is written, Vengeance [is] mine; I will repay, saith the Lord.
Contradiction with Isaiah 2:4
Speaks of a future where nations will not go to war, which is the opposite of the events in Judges 20:22.
Isaiah 2:4: And he shall judge among the nations, and shall rebuke many people: and they shall beat their swords into plowshares, and their spears into pruninghooks: nation shall not lift up sword against nation, neither shall they learn war any more. [pruninghooks: or, scythes]