vSAN for 2 Nodes

Dear Members,

Can we use 4x vSAN Standard per socket licenses + 1x vCenter Foundation for 2 node vSAN cluster? 

secondly if we need say 4TB usable capacity with RAID1 FTT1, how we gona calculate it for 2 node cluster?

my understanding regarding paper calculation is as follows

Required Usable Capacity = 4TB

Adding RAID1 Overhead = 4TB*2 = 8TB

Adding Slack Space = RAID Overhead +30% = 10TB

Adding Swap Space = Adding Slack Space + 20% = 12TB

Adding Disc Overhead = Adding Swap Space + 10% = 14TB

RAW Capacity Required per Hosts = 14TB / 2(as cluster is a 2 node vSAN cluster) = 7TB

Regards,

Moaz Anjum