PCSing with animals

Hello, for PCSing with pets, i know orders say one pet per person (up to two pets), but does the second person HAVE to be on that specific flight at the same time? my husband is going earlier than me to Spain but will be coming back to the states after we have our baby. I was wondering that since i’m still going to be sent out on his orders, if im able to take the two cats with me at the same time even though he wouldn’t be with me or if he would have to be with me so it was “one per person”. Sorry if none of this makes sense.