Hyper-V server CPU resource loading

We have installed Windows server 2016 server with Hyper-V on Dell R430 server, 2x16 Core 32Threats CPU.  We have build 2 guest Windows 2012 servers for each have 16 vCPU only. 

We found that even the guest servers CPU running over 70%, the host server only have 1 core full loading and other CPU only have few% loading running.

Is that anything we set wrong? Or anyway we can make the balance CPU load on the physical host?

Thanks a lot