What do I need to know?

My local animal sanctuary has over 250 ex batts for re homing. I have two beautiful Amber Star hens that are spoilt beyond belief.  I feel that I should take a couple of the XB's in order to help out a bit and let them experience the good life. Will I be able to just introduce them into my 4mtr x 1mtr run or should I keep them separate for a while? Any advice gratefully received.
Geoff.

keep them separate but let them see each other.
i put mine in at night and let them wake up with one another, we had some squabbling and i did put the one that kept pecking the new girls in a separate run inside the run so she couldn't chase them, it settled down after 2 days so she didn't keep chasing them, she is the boss so i suppose she was telling them that.
if you get some ex batts i would get a couple never put in one chicken in a already established flock.