As often as I hear stories like these, if I buy from someone hatching, I just tell them I’ll take a group of x birds. I plan on half being Roos. Then I hope for the best.
If they aren’t autosexing birds I haven’t seen anyone reliably identify them that young.
Assuming you meant 12 weeks, not months?
Chicken 5 might work out. The rest are Roos.
Not gonna say you got scammed, but the wing thing didn’t work too well. 😢