5 - Dell R610 with 96GB Memory in Each - Also has a 2 Port Intel 1000 Card (6 Nics Total)
What are you doing with 5 R610s that can't be done with two R720s? The memory count implies that the workload per node could be consolidated further.
The advantage 5 Means for N+1 one you only need to reserve 20% of resources in reserve. (now I'd argue 3 hosts is a GREAT cost sweat spot, as you only need 33% resources in reserve and you don't have to license 5 hosts which falls outside of the SMB kits for Hyper-V System Center, and VMware Essentials/Essentials Plus).
True, if the compute power of 4 hosts is required. That's an 8 processor requirement on day one to fall outside of the Essentials bundles. And a requirement like that usually will carry more than a 384GB RAM requirement. If...