Milk is definitely more important to him than solids in the first 12 months, so they should be trying other ways for him to drink his milk.
As they have a large turnover of staff, I too would be inclined to look into family day care. Get into contact with the family day care in your area, and ask them heaps of questions. You should be able to go and meet the lady/ladies in your area before agreeing to take him there.
I send my DD to daycare once a week. It used to be 2 days a week, but I've recently dropped it to one. The daycare she goes to though does not have a large turnover of staff, and she gets the same carer each day.