Matchmaking in War Inc. is dependent on how many medals a particular player has.
Based on a Commander's Medals, they are matched up against people within the same medal radius. In order to acquire more resources through looting, a commander needs to acquire more medals. This will allow a Commander to get to a position on the leaderboard where he is matched up against other active players of the same level. This allows Commanders to partake in battles with players of the same calibre.