I am a parent in a co-operative preschool in Northern Virginia.  Both my wife and I place a high value on the benefit that our child receives from this arrangement, and we are very happy to contribute time and effort to furthering this educational model.  For our preschool, at least, I do not believe that adding a requirement for each co-op participant to take 30 hours of training will add any value at all, even if every parent were able to do so; rather, the more likely outcome is that virtually none of the parent volunteers will be able/willing to meet such a high bar for training and there will be nobody left to actually participate. 

Our co-op has structure, training, and guidelines for the parents that are adhered to very carefully.  We are not professional educators, but we do care for the health and well being of the kids.  I neither believe that placing additional requirements on the parent volunteers would provide any benefit nor am I aware of any sort of systemic ill plaguing the co-ops of the Commonwealth that would be remedied by requiring such.