Sure, if it's raid or jbod it will work fine. I use Linux for this purpose and the performance is better than any NAS will ever be. I have a raid 10 setup with 5 disks with 1 as a hot standby and get over 400MB/s from them.
Are you saying to wipe the boot drive and install Linux then retain the computer functionality accessing the multiple drives via network? So in essence I would have a Linux computer that my new Mac would access its multiple drives through the network?
I was thinking that the motherboard and video card would be disabled then somehow the drives would be able to communicate through some other circuit board.
If I am going to keep the whole computer in tact and just network to the drives I might as well keep OS X. I could get some use out of the apps that still run well on that system.
If I made it a Linux system I might gain some transfer speed but I would have no other use for the Linux computer. You might say I would have no other use for the drive enclosure if I converted it to a dedicated drive enclosure. That would be true but I would also not need a monitor
Transferring data over a network is going to be slow compared to hardwired access using USB.
I have a relatively slow WiFi limit I cannot get around. I found that disabling the ethernet connections sped the WiFi up.
Ideally, I would have something like a hub so a single hard wire could access the multiple drives. This drive enclosure would use less energy because it would only power the drives and possibly utilize power saving features. A fully functional computer has the motherboard, graphics card and monitor to power. Efficiency is a virtue of a dedicated drive enclosure.
If I am going to really only be using a fully running computer for its multiple drive capacity I could get more out of it if I kept it on OS X. The apps that may run indefinitely on older OS and hardware are word processors and a PDF reader. I would use those to have reference material up on a screen so I could use the other computer (the new Mac) for production.
I hope all of this makes sense.
I may have misunderstood or not comprehended your idea.