Letting the horses come in the barn on their own is predicated upon how well the person bringing them in can communicate, verbally enforce the rules and point.
when I had to board there were 14 horses in two separate pastures. Seven came in on their own, then the other seven - who were lined up quietly at the other gate . The only time there were hiccups was when a new horse came and needed to be shown the drill. Otherwise things went smoothly.
When I had four horses, I never brought them in. They always came in on their own and went to their own stalls. It was a thing of beauty to watch them:)
when I turned everyone out in the AM, they went into the paddock one at a time, as I finished brushing each one. They politely passed the time, waiting for me to come down and open the paddock gate.
I was fortunate to have a strong and fair alpha horse (RIP Duke) who kept everyone in line, until I opened the gate. Nobody rushed the gate either. They walked quietly to pasture like the gentlemen I asked them to be.
If a person thinks they can see problems with this type of liberty, then you will and don’t do it.