15 After the Arameans saw that they had been routed by Israel, they regrouped.

Read 2 Samuel 10:15 Using Other Translations

And when the Syrians saw that they were smitten before Israel, they gathered themselves together.
But when the Syrians saw that they had been defeated by Israel, they gathered themselves together.
The Arameans now realized that they were no match for Israel. So when they regrouped,