Give the man a small bit of credit.

He's obviously not an imbecile, since you trust him to keep your child alive while you're at work. He may not do things exactly the way you do them, but he'll manage. I wouldn't ask the PO to hold them until you get off work. The sooner those babies are home, unpacked and have access to water, the better. Hang in there, it'll be fine. (Coming from someone who has also had to trust DH to take care of chicks for me when I've had to work. He managed just fine, and yours will, too.)