Provision a Multi Machine Service with VCO

I have a fully vetted workflow that starts at an IIS web Page and ends with a number of VM's being created for each of the users in this particular group.  This workflow works just fine  but the problem is when I point the workflow to a multi machine blueprint it fails.  The multi-machine blue print is a service but yet it is a VM of a type 3.  i can't figure out the automation or provisioning a Multi machine blue print.  Any help would be appreeciated.  Thanks