@Rahamim Levi , For the members of the Delegated Administrator, they can perform all administrative tasks within their assigned host groups, clouds, and library servers. But it cannot modify VMM settings, add or remove members of the Administrators user role, or add WSUS servers. We can see more details in the following link:
https://learn.microsoft.com/en-us/system-center/vmm/manage-account?view=sc-vmm-2019
I have create a domain user named test and create a "Fabric Administrator (Delegated Administrator)" role, add test as its member, choose the scope for All Hosts. When the user open SCVMM console with his own credential. It can open VMM console successfully without local administrator permission. Then I choose a VM and select "expand virtual hard disk" and find the operation can be done successfully. Could you confirm if we set the role the same?
I notice we get an error when change VHD setting. For this error, based on my research, I find tit may be related to DynamicMemoryMininumMB. We can try the solution to see if it can be fixed.
http://www.kuskaya.info/2015/11/20/after-configuring-vm-properties-in-scvmm-2012-r2-you-can-receive-the-following-error-message-vmm-is-unable-to-process-one-or-more-of-the-provided-cmdlet-parameters-id-1600/
Note: Non-Microsoft link, just for the reference.
Hope it can help.
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