They kind of are after you get used to them. You can tell by their face markings. The females will have a clear crescent on their cheeks while the males will have more solid brown heads. The one circled is a hen. The one in the back is a roo.
I kind of lucked into my snake guy. He was buying eggs, and I offered him some pickled eggs. He told me that he was feeding the eggs to his reptiles, and I mentioned that I get chicks now and then that need to be culled, and he started buying them and some extra boys now and then.
I sell some of my extras for snake food too, but I usually eat them. I have a customer who will take problem chicks for snake food. It saves me from having to cull them, and it's still part of the circle of life.
It sounds like you're doing the right things for the wounded bird. It's probably a male, especially since you said it was smaller. Males tend to be smaller than females.
You're going to want to get rid of 2 of the males in your non-celadon pen. It's better to do so before things get bloody...