That is a very good article with some really good information, but remember that is one person's opinions and experiences. Broody hens have been hatching and raising chicks with the flock successfully for thousands of years. Bad things can and sometimes do happen, but bad things can also happen when you separate them from the flock. They also require more work and inconvenience if you separate them. There are tradeoffs whichever way you go. For example, if you raise the chicks separately from the flock, you have to integrate the hen and later integrate the chicks. If the broody raises them with the flock, integration is not a problem. There will still be pecking order issues after she weans them, but they will have to go through that anyway.
It is a great article and it is full of good hints and information. I think it is definitely worth reading. Thanks for posting it.
Agree with Ridgerunner. All mine were raised in with the flock, and I will not separate future clutches unless they give me reason to. Some set their eggs there, too, although that did require moving the broody onto the correct pile of eggs several times (often as not, I would find another hen keeping them warm.) Worked out pretty well, really, but I am home to check on the chickens several times a day if needed.
I would not put a broody in something like a cat carrier, as I often read of people doing. I feel they need to walk about more than that every day. During their break, I see them go outside, dust bathe, scratch and peck, as well as hit a feeder and waterer. I have a 5x6 pen inside the coop, and a usually unused coop that's maybe 4x8, so there's room for a broody to set the eggs.