Depends how you set up the network I guess…
pc’s with access to the web, to the file server (most vulnerable), to the farm perhaps? Is all this segmented?
What are the precautions taken regarding rights, applications, services running on machines etc. etc.
Really hard to tell without a proper look.
I understand wanting to get the ‘best bang for your money’ PC wise, and seeing Win10 as a bit of a downgrade in the performance area. But keep on running a OS that is EOL for almost 18 months now might not be the best way to go forward.
With some tweaking in Win10, I’m pretty sure you will get more or less the same performance.
Especially for a render machine, you probably don’t need half of the services running anyway.
Might be a nice ‘project on the side’ just fiddling on a separate machine.