I think all you can do is explain in detail before they sign a contract and then when they bring things up reassure them quickly on how you do things and leave it be. They need to either accept it or find a hover daycare.

The world is wonky these days and kids are really kept on a tight leash. And i laugh as i write this as while they are on that tight leash (of being hovered over and suffocated) the exact same kids are running the show, ruling the house and running wild in parking lots because parents can't say no. Gahhhhhh

Maybe just tell them that kids act differently with a caregiver versus parents and kids act differently in a group setting versus alone with parents. you can't help but expect them to be worried you have 5 kids out with you when they can't handle one child.