In any relationship there are roles and responsibilities. For something to work for me those need to be flexible to allow for changes in circumstances, especially the health of the individuals, plus other things they may have going on in their lives.
So I struggle with prescribed roles that automatically make the third person subservient for that reason.
But, as I said in my first post, if it works for you successfully, then more power to ya. It wouldn't work for me, or the folks in my polycule, for the reasons I stated.
"Listen, or your tongue will make you deaf." - Native American Proverb