WD drive compatibility in RN1040 WD 8TB RED

I currently have two WD80EFZX WD RED drives in my RN104.  I would like to add another 8TB WD Red.   Does anyone know if the WD80EFAX will cause any issues?  I do expect if these drives will work together, that I will get the performance of the lowest performing drive(s).  This isn't a worry as this is used at home and performance isn't a big issue.

If the WD80EFAX isn't compatible, does anyone have a suggestion as to what I can add to give me another 8TB of storage?  I'm really not interested in having th replace all of the drives as the cost is prohibitive.