It's probably shipping stress that manifested. I've had good luck from hatcheries and I've had very poor luck from those same hatcheries. Usually correlating to how long they were in shipping and how the weather was during it
They can't always tell if a chick isn't going to thrive when boxing. Just because it isn't doing well after shipping doesn't mean it wasn't as active and loud as it's siblings when being sorted
My set up works way better without the lamps too, but my orders seem to survive better when they don't die under or right in front of the heating plates.
I don't buy that it causes aggression or affects sleep patterns, because often times I'll go out there and see dozens of snoring bodies...