I think they're right, but please try to stay flexible on it; I'm not entirely sure that stopping wouldn't wind up being worse. Perhaps he can pick them up earlier than normal one or two days a week instead, and take them to breakfast? (I don't know if your morning routine has enough time built in for this.) Also, look really hard at how much they're seeing him other than this. I'm not personally a fan of true 50/50 custody, because I found it too disruptive, but I'm a huge fan of the kids spending as much time with Daddy as they reasonably can. Some small part of what you are dealing with will improve with time as it becomes the new routine, but the hard part is going to be figuring it out. The answer is of necessity different for every family.
Sabra: Mama to Bobbie (3/02), Linda (1/04), Esther (10/05), Marie (11/10), Douglas (11/12), & Psalm (09/14; in Heaven)