Dell EMC mostly offers all flash storage, unless you go to the huge archiving storage options then you can get mechanical drives which should be NL-SAS drives. Even if you get sata drives( which I dont see any reason to go sata over sas in this), don't forget that dell uses it's own custom firmware from the drive, to the expander to the controller and even the MB. In this case I think it will be ok
to use sata or whatever they put inside if they made it as a whole machine.
But getting mix of vendors and drives behind sas expander I think is bad idea. It's called sas expander for a reason not sata expander. One vendor don't know what the other does, you know why hgst are most compatible with LSI controlers - case they made the drive firmware for quite some time.
Is there any other reason to even consider sata drive on sas expander, except to use cheaper drives ? Like picking consumer drives and put them on enterprise hardware ?
And what kind of spec is "green" drive ? That's advertising term not technical. What WD call "green" is not the same specs drive what hgst will call green drive or other vendor's green. I don't like this color scheme for dummies , that makes it even harder for knowledgeble person to understand what this drive do differently and what it specs are.