There might be a little fighting at first, but you shouldn't have any trouble as long as they have plenty of space during the day. Keeping them locked in a coop is how you end up with hens getting injured. The omega hen has to be able to run away from the rest of the flock to keep them from ganging up on her.
Free range hens are happy hens most of the time.
I work at home a lot of the time, so I can let them free range then, and the new girl keeps hiding in the coop as soon as the others start to chase her. The problem is that I have to be in the office this Thursday, and I won't be able to let them free range, so I'm not sure whether they will be all sorted by then. I hope this all ends soon and they can just be happy coop mates!