I think it depends on what the birds have access too, grasses and greens and bugs and such. If you have a large run that hasn't gone to dirt yet, they would be getting the benefits of free range in a safe environment. Same with the tractors, as long as they're moved often enough. That wouldn't actually be free range, but they're getting the same benefits as free range without as much risk.
Sand/dirt/gravel runs don't give the benefits of free range, so these birds would be called "cooped".. but not caged. Caged is just enough living space to survive, but not enough room to take a feel-good wing flapping turn around the run.
The best and safest IMO is "Cooped Free Range", in the form of tractors or rotating runs to keep the grass/weeds available. Not really free range... but.. same diet supplementing.
True free range though, is fun if you have the room. It's neat to go out and call the chickens, and have them come running for a treat from all directions. But, you have to worry about if they'll all come back, and you have to do a head count like twice a day, and keep your ears open for the sound alert in case you can shoo the predator away.