Welcome to the forum @tbag!
Depending on who you ask, you will get different answers. But the advise from Storj is to run one node per physical HDD. This should in the long term be more profitable to you. I agree with that assesment.
However, opinions vary and this topic may be interesting to you: RAID vs No RAID choice
If you already have an array and you plan to use available space, you should know that there is no advantage to running multiple nodes on the same storage device (whether that is an array or individual disk). Nodes on the same network are treated as one node for traffic allocation, so running multiple nodes does not get you more traffic or data.
Final note, there is absolute consensus that you shouldn’t be using RAID0 or JBOD or similar multi disk options without redundancy, as the loss of one disk would have you lose your entire node.