Is my Fusion Drive set up on my iMac correct? or is there a fix?
Klanomath and all - 

Objective: Properly erase an iMac running Catalina built in 2013

A functional computer should be able to be erased. I was trying to determine the viability of the computer>

Background: I needed to erase my iMac (running Catalina) with a Fusion Drive and was told that ERASE should be accessible while in Disk Utilities in Internet Recovery Mode. ERASE was not accessible on my iMac.

RESOLUTION:  My understanding is now that ERASE will NOT be accessible if a Mac has a Fusion Drive and is running Catalina in Disk Utilities in Internet Recovery Mode. 

In the end, I could not use Apple's How to erase a disk (https://support.apple.com/en-us/HT208496) documentation, but I can use the directions in Apple's How to split a Fusion Drive (using the Terminal) https://support.apple.com/en-us/HT207584. My understanding is the latter splits or fixes a split, erases and re-fuses the Fusion Drive. 

As I can now erase the iMac using the How to split a fusion drive documentation, I have been told the computer is useable. 

Side note:  I found and so did the people I was working with, the Apple Documentation to be confusing - it can be interpreted in a variety of ways and is not clear with respect to Fusion Drives and how to erase them.   

If anyone sees an issue with what I wrote, please feel free to chime in.