ORK.Game.ActiveGroup.Leader is a direct reference to the player combatant.
If you have the instance of a combatant (class Combatant), you can access it's variables via the Variables property.
If the variables are only changed on that combatant/object depends on the object variable setup. When used as Local Variables, yes, otherwise it depends on if their object ID is shared with other combatants, in which case it'll be changed on all of them.