I personally wouldn't put them all together yet. Especially depending on the condition of your battery hens.
I like to quarantine my new chickens for at least 3 weeks. It is a stressful time and introducing new chickens that may carry things yours aren't exposed to could make them sick. In my opinion battery hens are at an even greater disadvantage and at 19 weeks old the cockerel will be interested in mating which could further stress them.
I thought as much, ill give them a few weeks. What do i look for in a great CL rooster?