Why is Over-Allocating a VM Bad?
Why is is so important to allocate just the right amount of resources for your guest VM running SQL Server? We all know the problem with an undersized system; however, what about an oversized system? What problem could that be? Here are a few common issues to consider:
Over-allocating CPU causes poor resource utilization across all the guest VMs
Over-allocating memory unnecessarily increases memory contention and overhead on other guest VMs
Having more vCPUs assigned to the VM can have an impact on licensing.
There are some good points in the post, so check it out.