Additional SQL Server features and topics not covered by specific categories
This is a technical forum, and your question is a legal one. You cannot get an authoritative answer here. If someone here would give you the nod, and you are later license-audited and the auditor thinks you are under-licensed, referring to this forum will carry very little weight.
You are better off contacting your local Microsoft representative to get an answer in writing.
I recognise the setup you describe from the Licensing Guide, but it's a little special when the primary is a physical machine and the secondary and the DR nodes are VMs.
My gut feeling is that you would need another 8-core licenses, but I did not open the license guide to find any confirmation for this. My reading of the licensing guide is not any better than yours.