Sizing VMs
When choosing number of cpus per socket of VMs you want to pay attention to the processors of the host the vms are running on. You want to maximize the number of vNUMA nodes that are available to the VM. This is based on the architecture of the processors in the host.
By using the least cores per socket you will usually get the best performance.
Be careful as some applications can only use one socket, SQL servers can cause a problem here where you want more cores in the socket.
See here for detailed information https://blogs.vmware.com/vsphere/2013/10/does-corespersocket-affect-performance.html