You can move them around. Go to your den, click Organize and move them where you want them. Then click the button that says Save Position. Though, I heard that you can't do it on mobile for some reason? Idk if that's still the case but if you're stuck on mobile then you might not be able to. :/ Maybe someone else can chime in on that since I'm not sure
I checked it out on my phone and while the organize button is there, there doesn't seem to be any way to click and drag in order to move them. I found a bug report here if you wanted to add your voice to it, I'm not sure why the thread didn't pick up much traction. Hopefully this is something they fix one day.
To answer your original question about how wolves are organized, when I move wolves between dens it seems to automatically sort them by ID.
