Sideline management is a continuous and progressive process, often subject to lapses in judgment caused by the emotion of the moment. Bad habits are best corrected by consistent and constructive correction and adjustment is often a progressive consequence.
Controlling the restricted area is NOT an aimless demonstration of power, it's a serious and important preventive measure designed to protect the safety and well being of both officials and all sideline personnel, who routinely are subject to distraction either by their attention to necessary focus on game action, or emotional observation of the game. Collisions within the restricted area are serious matters that offer the potential of extreme physical consequences, that are totally unnecessary and easily avoided.
In many instances a simple, direct, reminder of stated restrictions, and the reasoning behind them is sufficient to eliminate problems and congestion. The number, and intensity of reminders is unique to each sideline, within each contest and the manner in which reminders are received, impacts the process which, if not eliminated, culminates in eventual warning and if necessary penalty. It's NOT about ego, it's NOT about territory or habit, it's all about common sense and relative safety.
Proper sideline management during prior contests helps make your job that much easier, as much as your proper sideline management, hopefully, makes the job at next week's sideline easier, and safer.