To me the single nic/double nic decision is a tradeoff between simplicity and complexity, and where you want that complexity to live. A single nic may be physically "simpler" but you need additional software complexity with VLANS and a VLAN aware switch. A double nic is mabe physically more complex but it allows you to have a simpler software setup (no VLAN's)
There are a number of US states that have moved off Microsoft (mostly to G-Suite) and a number more that are considering it. And yes it won't be EVERYone (you can pry excel out of accountants cold dead hands) or everyTHING (obviously mainly Windows) but it's at least a blow against the pricing and quality issues from MSFT
"..for all of Trump’s ills, I see him as a sign of the underlying dynamism of the US. Who else would have elected so whimsical a leader to this high office?"