Those chicks that are perfect sized now will grow in the next 3 weeks and will be towering over the newly hatched chick. The new chick will be trampled and pecked by the older chicks that are much more advanced. And feathering out at different times.
3wks!?! This chick is due to hatch this coming week! Lol Of the 7 chicks I have now 3 are much smaller than the other 4 so those are the three that I plan to put this new chick with. At least one of them anyway.