I wouldn't have a problem giving him a bottle if he's still just 12 months old and it soothed him to sleep. I agree that I like wee ones to be weaned off soothers and bottles as soon as possible, but between a year to 18 months is my goal for that. But when a child is new at my daycare I cuddle them and sing and get them to relax for at least the first month. Then the second month if they aren't getting it I sit right by the playpen and keep laying them down over and over again no matter if they are screaming or not. I do this for a few weeks until they learn I'm relentless! They learn to go to sleep pretty fast for me. I only had one little girl who took months but it was when I was still new at this.

Naptime is precious to me as it probably is to you because it's the much needed break in the middle of a long, busy day. I do ask parents to get their children onto our daycare nap schedule as much as possible before starting care and then when they are full-time they fall into our routine usually within a short time. But you mentioned that he isn't full-time yet. I bet he will get better once that happens.