How much fighting is normal when introducing

[hodor]

You will not like this answer but the amount of fighting is directly related to how badly the two chickens in question want to dominate each other.

The new plymouth rock one is happy to stand down, she just runs away. Only the one of the existing two - the Ancona - is trying to be dominant, the noise of any fighting scares the Araucana and she runs away too!

They are doing pretty well, the rock gets within a few feet before the Ancona displays aggression now or if the rock is spotted entering the coop. The Ancona appears to be trying to crow (just makes a funny sound) for the past 2 days however which I am guessing is dominant behavior for the girl!