Global Deployments: Is Multi-tenant or Intra-tenant locations the best way to go?

I have been tasked with building a PoC in Azure to "simulate" a future global deployment where data transfer time is important factor. The actual deployment will be using fully on-prem resources. So, as odd as it sounds, I am looking for the worse performance possible between the two options.

Architecture A (single tenant):

1. Create a single Azure tenant in the US region
2. Create a Resource Group with a US-based location
3. Create another Resource Group with an EU-based location

Architecture B (dual tenant):

1. Create an Azure tenant in the US region with a US-based RG
2. Create an entirely separate Azure tenant in an EU region with a EU-based RG

Would the dual-tenant structure above make any measurable difference one way or the other from the single-tenant (assuming all vNetwork, VMs, etc are identical)? I am thinking the single-tenant setup would be faster since (presumably) the traffic never leaves the Azure Service Fabric. But that's just speculation.