We have 20 (what were purchased as) Cornish X that are more than 7 weeks old. They seem VERY small compared to what I'm reading about others, and very big difference in size from what look like obvious roos and hens. The 8 which are larger are probably 3-4 times the size of the smaller ones. I'm wondering if the hens might be leghorns that got mixed up at the feed store. They've been on 24% protein starter/grower feed free choice. We were hoping to raise them large for roasters. Any ideas? Working on attaching photos.