Hi,
First, setting up 1 vCPU with 8 vCores or 2 vCPUs with 4 vCores each or well ... anything else won't change anything about your problem. This setup is only for licensing purpose. Some products are licensed on a per (v)CPU basis.
About your CPU performance problem, did you noticed any problem with your Storage Devices ? Same question with your vmnics ?
Do you use memory overcommitment ?
Can you detail your physical configuration (CPU OK, but also memory quantity, storage type (iSCSI, SAN, local, VSA), Network (number of vmnics, speed, ...), and your 3 VMs configurations ?
Also, you should study yor %READY graph to see if it's too high ?
Regards.