@[email protected] is correct, it's the order you connected them in (see tldp). Use UUIDs or devices lables for consistency or connect them in the order you want.
AFAIK the a-b-c enumeration comes from hardware, so for example whichever sata port you use in a motherboard would always get the same identifier. You'd need to turn off all four nodes and check the disks are indeed connected in exactly the same ports. If that fails, then I'd assume the motherboards are from different batched or soldered differently for whatever reasons.
Gnome says that, it will turn on osk and screen rotation automatically when in tablet mode, but that doesn't work in my laptop. Is there anything I can do to fix this?
It has all the hardware for a convertible laptop. Right now, I am using an auto-rotate gnome extension, and it works, but for some reason gnome doesn't recognize when I flip my laptop to go into tablet mode. Although my firmware recognize it properly, seeing as they turn off keyboard light automatically. So my guess is, the problem is on Gnome's side.