No offense but if you have this level of questions you might consider that you probably shouldn't be running a freestyle training event with dozens of people.
There's a few different formats for running ranges. Having one person to manage the overall range and multiple, focused RSO's on individual bays/ props/ drills to issue load, unload, and clear instructions and watch the shooters for safety is a time tested method. RSOs don't need to be walking off, so an independent free roaming adjudicator should be present. PRS matches use a looser version of this and it mostly works because people are only loading, shooting, and unloading on command. People likely aren't going to self-adhere to some safety rules like range fan, safety while moving positions, and correct unload sequence with semi autos, but they will be more conscious and diligent when they know someone is watching.
A hot range is defined as everyone is loaded and holstered/ slung all the time and keeps mags and guns topped off at will, without the supervision of an RO. The scenarios where hot ranges are run is when a specific unit with a very high level of selection, training, and SOP exists. Having people roam around with loaded guns is bad idea when you're dealing with John Q Public. You have no idea what the level of experience, expertise, or mental capacity is.
In a public range event where the attendees are unknown quantities, no one should have a loaded rifle until they're on a station or in a shooting box and an RSO/ squad mom/ safety clarifies with the shooter what the drill is and is ready to administer.
Have an idea about how each person is going to shoot the stages or props and give a safety brief prior to the event starting and outline that. Don't let anyone shoot who didn't attend the safety brief. Think about a basic, non-scenario specific, broad spectrum list of safety protocols you need to inform everyone of. "Don't point your gun at anything you don't...". "know what's inline with your target..."
You would probably be surprised how high up in the tiers these basic things I've outlined are followed religiously. As a matter of professionalism.