Hi @Kamil
If you are using hyper-v to host your virtual machines you can choose Datacenter version to be able to activate unlimited guest VMs as mentioned in the following link : Locks and Limits If you choose standard version on hyper-v host , you have to buy 4 additional standard licence to be able to activate your 8 VMs.
https://www.microsoft.com/en-us/windows-server/pricing
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