This is more a post so that I can recall what the final solution was should I ever run into this again.

After configuring our new server and installing two hyper-v virtual servers on the host OS, I noticed that the network transfers within the guest OSs were BRUTALLY slow. As in < 1MB/s. I assumed that I had configured the Virtual Switch incorrectly or that all three servers were using the same NIC (even though I configured them to all have their own dedicated one).

I beat my head against the wall for 20 minutes and then turned to every IT workers favorite tool Google. I found this article which walked me step-by-step through the solution.

A quick reboot later and the network speeds were back to normal.