Good luck with the pairing Miss. Thinking of breaking my new leghorns into 2 pullet pens (2/3 I have 5). They are bred, for now were with roo until yesterday when I got them. And have them penned with other pullets and a immature cockerel. My idea was to do a rolling pen mating or clan style. But all chicks from these will be related thru the sire now. Might do this and then swap blood after a couple generations. To keep a slightly larger gene pool until I get more WLH blood. I do have an Austra-White Rooster that I can add into the blood if I need to later.
I have 3 pen projects at the moment, BSL, Austra-White x CX and the WLH with 3 RIR that were bred at same breeder all pure. My red pullets from last spring were suppose to be Red Ranger, but I thinking more RIR. Feed store had NO IDEA what they were doing. But they lay great eggs so I don't complain. Just never got any size to them beyond average hatchery DP breed.
I have 12 replacement cockerels brooding now. Only pure rooster I have at this time is 1 BA. Everything else is BSL from last year. And the 1 A-W. BO, RIR, BA, BPR. Some of these may be pullets though. I am betting 3-4 RIR are but I'll have to see. These are the 4 breeds I have pure pullets for. A lot of sex-links and a few mutts in the general flock but they supply the eggs I sell, 20+ dozen a week and still not meeting demand I have. But pay for feeding flock.