I almost wonder if battery hens would be safer than random CL birds in the long run. At least they're usually vaccinated and kept away from outside birdsI’m sorry, but this is a bad idea.
You don’t have the space not proper equipment to quarantine all these different birds you’re bringing in.
And I know you don’t mean battery hens.
It doesn't matter.
Even the glossiest, prettiest hens can bring disease. You'd have to quarantine every individual or group that came in, and your setup won't work for them.
Also, what would you do with them? Sell/rehome them once they're healthy again? Who would buy them? You'd be stuck with them - you'd have given away your happy flock for a group of strange, separated hens who probably won't be laying.