I bought 3 "pullets" from BYC. They are now 10 wks. old. One turns out Roo and is being re-homed next weekend. I'm trading him for a 10-wk.old RIR/X pullet. After 3--day confinment, are they still young enough to put in the same coup, or will i have problems? Or, should I just try it and watch carefully?