It can actually make it easier on the kids if there are other kids in the daycare when they start instead of just the caregiver and child - sort of a chance for diversion. I have started kids at the same time and found it easier than one at a time in the sense that they didn't automatically choose me as their comfort item for daycare and instead were more inclined to play with the toys and show interest in what the others were doing.

What about having a couple playdates with moms and kids so everyone gets to meet everyone else and then do just kids.