AFAIK Fusion 11 isn't supported on the 2009 Mac Pro, and fusion only supports virtualizing boot camp VM's based on what Apple supports in boot camp on that machine. Both are limited by the actual capabilities of the CPU and other hardware, not what the BIOS thinks it is.
One thing that definitely won't work is copying fusion configurations for boot camp VM's from one machine to another. You can copy standalone VM's (not on a physical drive), but even then, you'd need to have the VM configured in a lowest compatibility mode. That's probably your best option in this case - create a regular Windows 10 VM in Fusion 10 from scratch.
I hate to say it, but that's really old hardware - it's probably time to look at upgrading to a new machine.