Drive Setup

[Rogue26]

Hoping that I can get some suggestions on the best setup. I have just started to play around with Unraid and plan to mainly use it for docker applications. I have a synology DS1019+ that I am using for my storage needs.  

My current setup is:
2 - 4tb drive making my array  (1 storage, 1 parity)
2 - 500gb NVME pool drives
1 - 240gb SSD pool drive

I was thinking that I would like to have all of my docker related stuff on one NVME, my Usenet downloads going to the other NVME while they are being handled prior to moving to the synology, and possibly use the SSD as my Plex cache. It was suggested to me that I should set the NVME drives up as a mirror and store all the docker, downloads, and Plex cache on it.  This seems like a good idea but with my lack of experience I am not sure how to do that now that I already have them setup as individual pool drives.  Currently one of the drives is setup to handle the downloads from one of the docker applications but the other two aren’t used for anything. 

Being pretty new I am not sure if this is the best use of the drives or how to go about making it happen.  Wondering 

Any thoughts or help would be greatly appreciated. 

Thanks