I hadn't really noticed the tail difference because I was busy looking at the wings but you are correct they are not the same. I will keep my eye on that very interesting observation!!! I'm curious to see if her tail will continue to be different as they grow...
I got a few rir pullets from rural king and I got a few cornish and isa from tractor supply. This is the only yellow bird in the bunch she/he is definitely different. A few days over 7 weeks old