Method 1 (script): (the only method to change the combat mode of individual units instead of whole group)
1. Create a new group,
2. Temporarily move the units to this new group,
3. Set combat mode for the new group,
4. Rejoin units back into their original group.
5. Use the combatMode command on one of those units.
6. It always returns "YELLOW"
_units = groupSelectedUnits player; // just some array of units
_sideUnits = side (_units#0);
_originalGrp = group (_units#0);
_tempGrp = createGroup _sideUnits;
_units joinSilent _tempGrp;
_tempGrp setCombatMode _desiredCombatMode; //e.g "RED"
_units joinSilent _originalGrp;
Method 2 (engine commanding menus):
1. While being the leader of a group, use the commanding menus to order a certain unit to hold fire.
2. combatMode returns "YELLOW"