With that logic, the SD would've made Elizabeth go with Mael, the strongest in the race she rules.
At this point this theory overanalyzes everything too much. Also it completely reduces Elizabeth's character.
The theory was created that the SD used Elizabeth by fans, because Nakaba has given her no purpose in her clan. She does not seem to serve the SD in any seeable capacity, or really do anything at all.
I know you all in the Eli squad hate it but Nakaba gave people ranks, fancy titles and job descriptions for a reason.
She dislikes fighting and stays off the battlefield most of the time.
She’s not the leader of the goddess clan in place of her mom on the battlefield.
She’s not the hope of the clan.
She’s not the almighty invincible heir to the goddess clan.
She’s not Mael and Ludo’s master, the strongest two goddesses.
She’s not the goddess queen’s personal executioner/representative.
She’s not the goddess queen’s personal trusted assistant she thought about giving half her power to before splitting it among the 4 AA.
She’s not an AA herself.
She’s not the leader of the 4 AA’s.
She seemingly does absolutely nothing.
She’s just Lady Elizabeth, the SD’s daughter, and that one goddess who seduced the legendary Meliodas.
That’s her title.
Seeing as that’s not actually serving the SD in any way, people came up with the idea that the SD must have unknowingly used her without her knowing, cause it’s the only thing she can get out of her because she does nothing else.
You say that “degrades” her character, but either the SD used her for something, or she does absolutely nothing at all.
Which is it?