I have since realised that I can use the unraid array as my media server (so this negates the need to have one of the windows 10 vms altogether). And just create the 1 vm for my DCS server. So in theory I can just use the unassigned drives for the aforementioned vm. I have a os drive and a storage drive (which contains the DCS install.
Now all I have to figure out is how to Make my currently installed hard drives run on the vm without having to install windows again etc