By the way, I probably also read this when I first set up the nodes leading me to believe it was fine at the time.
Here it specifically mentions using raid arrays. Although it says it’s not recommended, the only downsides mentioned is related to the nature of raid itself and says nothing about IO limitations or any other issues with running nodes on a raid array. Just pointing this out as it should probably be changed or taken out altogether knowing how poorly it performs running multiple nodes.