1)
Verse 4 says that Hashem gave the Kena'ani into Yehudah's hand, and they struck them. Why does it say now that they fight them?
1.
Malbim (4,5): First, the army camps went out with their officers around Bezek, and there they killed 10,000 men. Then they came to conquer the city itself. Adoni Bezek stayed inside the city to fight for it when needed, unlike Melech Ai who left his city open.