OET interlinear HERO (JDG) 18:21

uW Translation Notes:

Note 1 topic: figures-of-speech / explicit

וַ⁠יָּשִׂ֨ימוּ אֶת־הַ⁠טַּ֧ף וְ⁠אֶת־הַ⁠מִּקְנֶ֛ה וְ⁠אֶת־הַ⁠כְּבוּדָּ֖ה לִ⁠פְנֵי⁠הֶֽם

(Some words not found in UHB: and,they_turned and,they_went and,they_put DOM the_little,one[s] and=DOM the,livestock and=DOM the,valuable[s] before,,them )

The author assumes that readers will understand that the Danites put these vulnerable people and valuable possessions in front of them because they expected Micah and his neighbors to pursue them. You could indicate this explicitly in your translation if that would be helpful to your readers. Alternate translation: [And they put their children, cattle, and valuable possessions in front of their soldiers, expecting that Micah and his neighbors would pursue them from behind]