I think it has a lot to do with what you’re comfortable with.
Are you going to store just movies and TV shows? Then yeah, a RAID failure that can’t be recovered from for one reason or another won’t be the end of the world.
Storing priceless family photos that for some reason you’re ONLY storing here? Maybe go to the extra expense and do it “right.”
You’re introducing multiple points of failure to a system designed around protecting against failure. Everyone is going to argue against it because it’s additional risk that can be avoided. There’s also a chance of the host computer chipset going wonky and disconnecting the devices (I’ve seen it enough times it IS possible. Usually a reboot fixes it, but odds are the RAID would still need rebuilt), or a bad USB cable, or you forget that it’s in a RAID and plug it in to another computer, or any other hypothetical that seems unlikely but could happen.
If you want my advice that you didn’t ask for, plug them both in and mount them separately, put all data on one of the drives, then use a tool like FreeFileSync to copy all data over to the second drive drive. You’ll miss out on the theoretical 2x read speed, but this way if one or the other DOES come disconnected, you just need to plug back in and you’re back working without a chance of a RAID needing rebuilt.











I’d tell you why that is but due to some vague, shadowy group that I won’t ACTUALLY name but give vague hints about, I can’t tell you.