As the OS is 2008 R2 Enterprise, you can run just Hyper-V on the physical host and compartmentalize each role(s) in its own virtual machines. This way configuration changes/updates in one virtual machine does not affect other virtual machines or the host. The down side is additional memory and disk usage, but they are so cheap these days.

Virtual machines are also ideal for testing. It is easy to create a new machine, test the software and delete the machine when done. But don't activate the test virtual machines though.

IIRC, Windows Server Enterprise license entitles you to 1 physical host and 4 virtual machines.