Day care children here nap on my schedule not their own. When a new child joins, I'll try and consider their schedule for the first week or so whilst they adjust to this environment but then I move them onto my day care schedule.
For those children who come very young and who still have two naps, I find a "power nap" soon after they arrive in the morning, which I will wake them from after max of 45 mins, seems to help and then they go down with everyone else after lunch.
We have a set schedule were we aim to go out to the park or walk along a private track we have access to which leads to a private beach, before heading home for lunch. We leave the house around 9am so everyone needs to be awake, have had their morning snack and bum changed, so we can go.
Try and move them onto your schedule rather than having all these individual children on their own. It makes life much simpler.