Contradiction with Genesis 19:30
While 2 Samuel 10:16 talks about people gathering to fight, Genesis 19:30 describes Lot and his daughters seeking isolation in a cave.
Genesis 19:30: And Lot went up out of Zoar, and dwelt in the mountain, and his two daughters with him; for he feared to dwell in Zoar: and he dwelt in a cave, he and his two daughters.
Contradiction with Exodus 14:13-14
2 Samuel 10:16 involves an offensive gathering for battle, whereas Exodus 14:13-14 depicts God advising the Israelites to remain still as He fights for them.
Exodus 14:13-14: And Moses said unto the people, Fear ye not, stand still, and see the salvation of the LORD, which he will shew to you to day: for the Egyptians whom ye have seen to day, ye shall see them again no more for ever. [for the...: or, for whereas ye have seen the Egyptians to day]
Contradiction with Matthew 26:52
In contrast to the battle preparations in 2 Samuel 10:16, Matthew 26:52 warns against taking up arms, saying those who live by the sword will perish by the sword.
Matthew 26:52: Thinkest thou that I cannot now pray to my Father, and he shall presently give me more than twelve legions of angels?
Contradiction with Isaiah 2:4
2 Samuel 10:16 shows nations mustering for war, but Isaiah 2:4 prophesies a time when nations will no longer learn war.
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]
Contradiction with James 4:1
2 Samuel 10:16 describes external battles, whereas James 4:1 attributes wars and fights to the internal lusts of individuals.
James 4:1: From whence [come] wars and fightings among you? [come they] not hence, [even] of your lusts that war in your members? [fightings: or, brawlings] [lusts: or, pleasures]