Create a new mission
place 2 groups (one of each side: Blufor, Opfor);
create a waypoint "move" for each group to make their pathes crossing;
change only behavior for each waypoint to "careless";
place player as another unit civilian or setcaptive to observe.

AI units progress with weapons lowered and don't use them, but they will throw (hand only) grenades in direction to enemies. Then, after wounded cases or epecontact (I don't know exactly), some units will shift to hand gun and will fire with it!

A little video here: https://www.youtube.com/watch?v=7EYZd1OpSJo

NB: (colors are for fun: blue for Blufor, Red for Opfor, Green for friendly indep, yellow for enemy indep, white for civilian or captive, black for dead units) You can reproduce without them!