Our already small flock of 3 has recently been reduced to 1 due to an overly excited dog. We are looking to introduce new birds and grow our flock to 4. We aren't sure if we should get 3 different breeds or even worry about it. We've heard different stories. Some say "birds of a feather..." others say it doesn't matter, the birds will establish a pecking order. We don't want our Sexlink to get picked on after all she's been through. What to do, what to do?