Okay, I refrained from taking the Elaine/Fiona thing seriously. I feel like I want to make a point though, so I'm going to give some real thought to this response.
In terms of Elaine and Fiona, they aren't "two sides of the same coin", they are both literally the same side. In fact from what I read, both sides dislike the other side for the exact same reason. I can even say my dislike for elaine, but not fiona is linked to it, HOWEVER! Fiona is just as guilty as elaine is, so why do some like one and not the other?
At first you'd say "thats not true, they are totally different!" but the fact is they aren't. They both had the same goal: What was in the best interests of Becca and her family.
I'll start with elaine, cus shes easier. She put the MC through a tough event, forcing him to call martin. The actual victim in that scenario WASN'T the MC. It's martin. He was determined to be a threat and detrimental to the family, and so he needed to be cut off and "closed" to resolve the family issues. She ruthlessly and without hesitation pushed to resolve that conflict, because its for what is best (even at the expense of using her first grandchild).
Now moving on to Fiona, as much as she is bae, I understand the whole "she tried to rape the MC" argument. It's easy to say thats totally different from elaine, her method is illegal and unforgivable. The thing is, Fiona's goal was the same as Elaine, but the target is different. Elaine's target was to eliminate martin, Fiona's aim was to assess as if you were martin. Her goal was to contain, control, and remove had you proven yourself a threat/danger to the family. You weren't accepted. She used very heavy handed methods, and I can't claim to know how that will change on the submissive path, but the fact is she also forced a bad event with the intent of promoting the greater good.
Had Martin truly shown up and created issues with the family, I have no doubt elaine would have resorted to extreme tactics like Fiona, if it meant the better outcome for the family.
My final point, and this is something I take from life experience, the reason Fiona and Elaine don't get along...is they are the same. People who are too similar just seem to rub each other the wrong way. How people are split, is funny, cus they both did the same thing, the difference is were you the main target, or were you the means to eliminate the target. Thats where people are getting hung up.
To finish off this massive wall of text (sorry), I think this is all wonderful. I think its a great testament to the writing and the dynamic of the characters that allows people to engage in such discussion, and I hope that people can respect each other, even if they may not agree.