Formations - Kieranator/BadArma GitHub Wiki
Using a formation is simple: when the leading element moves, everyone else moves to maintain the formation's general shape, matching the leader's pace. Don't stress trying to maintain a perfect formation, deviate a few meters to take cover during a halt.
Know wedge (top left), line (bottom left), and column (right).
Default to wedge, your fireteam leader will change your formation based on the situation.