Hi, KILLSWITCH9027!
Thanks for reaching out to Microsoft Community and posting your concerns. We are sorry to learn you have issues running Ubuntu via Vmware with your Surface Book 3. Thanks for taking the time to let us know about this and allowing us to help you out. I am afraid to inform you that running a non-Windows OS on the device is not advisable. However, you may check this page to learn more about How Windows Defender Credential Guard works. There are other articles there related to Credential Guard that may help you out as well. You may read further there for more information.
This may not be the answer you're looking for, we hope to have helped you address this accordingly.
Kind regards,
Janette_Z