Are they both crying at nap time? oh man. Is one more likely to go to sleep quicker? You have to use a lot of strategy thinking when doing this job, I have found. every child is so different that what may work for one will never work for another. I guess try feeding them both at the same time, I really think though by the sounds of it, you need to lay the co-sleeper down first, you may have the most issues from that one. Hopefully they just cry for like 15 20 minutes of a I'm alone whine and then fall asleep? Hope it goes well.