I thought we are talking about NAS'es.
As much as I want to take you seriously, I can't. When I was shopping around for a NAS, I was strongly debating between buying Synology, QNAP or build my own with Freenas with Xeon/Avoton based hardware. WD hasn't even been on a remote thought or map, let alone being considered.
I went with an Intel Atom based Synology, DS713+, and by golly it has been a good solid choice, both performance and stability wise. I would still build my own now though, because manufacturers have a nasty habit of locking you in with their products. Apple doesn't do this.... /s.
If you want/need a proper NAS, you can start counting the minimum number of disks from two (RAID 1, you know), otherwise you're wasting money.
And going back to your post, I don't think your mac has anything to do with the performance and stability of your ARM based NAS. Admittedly, Finder is a steaming pile of crap for mounting and navigating mounted filesystems, but it can be avoided by using Pathfinder.