I don't know. I think she, Lex and Vandal Savage meant to be the dark trinity of the light. All the other positions either have turnover or are expendable in the sense like Brain/Ultra-Humanite and Klarion they are there to fulfill a specific function such as the science/tech person or the magic person.
Though I do find it fascinating how the show has elevated her as a supervillain (compared to the big names like Vandal/Lex/Ra's) when she was pretty much nonexistent in the comics and really shows imo how a lot of Weisman's sensibilities of DC came from his time working there during the 80s when the character was more prominent then. It really demonstrates I think that the production side weren't tuned into the current DC comics that were being published during YJ's development (or else they'd use someone like Black Adam) as opposed to the elevation of Manta for example that was partially due to Geoff Johns.