That's probably possible, but assuming you have 10 VMs on 5 hosts, would you want to purchase 50 Standard licenses for the worst case scenario (all VMs on one host)? Or think of the same scenario with Enterprise licensing. Due to the requirement of "peak" licensing you'd need 13 Enterprise licenses for each host to cover the 50 VMs!
Depending on the environment it is most likely the least expensive option to have Datacenter licenses if you want to fully comply with MS's EULA.
André