The system you describe puts your safety in other people's hands. Do you want to be in control of your safety or not? Do you want to be subject to a lethal crushing head injury because some member of the crew is unclear or some idiot does not follow directions? Do you give a crap over whose fault it is when you have someone bash you in the head with a tank from 4 feet up?
IF you follow the rule of going in the proper order AND you refuse to roll if you see someone roll in before you who is forward of you, then YOU are in control of your own safety. The diver who rolls in could also be killed if they "land wrong" on another divers tank valve, for example.
I personally want to be in control and not subject myself to injury because other people mis-communicate for a few moments.
I foolishly thought from your original description that the crew was in charge of that system as well. I don't think you are saying that the divers in your system do it all on their own, with the crew totally surprised when they enter the water. Or are you? I have done back roll entries all over the world, using a variety of systems, and in every case I have used whatever system was ordained by the crew. I have never seen your system used anywhere. It may work just fine, but I have never seen it.
On a boat the crew is in charge of the entries. So what are you saying these divers should do if they don't like the system being used and prefer yours? Are you saying that they passengers should conspire among themselves to do it your way and roll off on their own, raising a middle finger to the crew as they drop?