'Groups' in the Bible

Whenever the Israelis sowed their crops, the Midianites, the Amalekites, and certain groups from the east would come up and invade them.

Then all the Midianites, Amalekites, and certain groups from the east gathered together, crossed the Jordan River, and set up camp in the Jezreel Valley.

The Midianites, the Amalekites, and certain groups from the east lay encamped in the valley, as thick as locusts. The number of their camels couldn't be calculated they seemed as numerous as the sand on the seashore.