We're new to backyard chicken raising and have a small flock 3 +1, which includes 2 Barred Rock, 1 RRR who've been together all their lives and an Auracana we are hoping to integrate with the other girls. Looking forward to getting to know people here and I've already found great information in the forums, in the newsletter, and on the website. Thank you!
Best wishes and have lots of fun with your flock!
Welcome to BYC!!! 
but it doesn't seem to be working. Sometimes to find out what works in different situations, you have to experiment a bit. What if you separated the 3, say, and put only one of them in with your araucana? Or if you secluded the biggest bully for a while to possibly change the dynamic of pecking order? Maybe you could try putting the araucana on the roost at night (in the dark) with the other birds.
We are glad you joined our flock!