I think you’re missing the point. No one needed to replace Jeyne, certainly not a character played by an actress only 18 at the time of filming.
D&D have cut and changed so many things- from Arianne and Lady Stoneheart to Young Griff and Jon Connington- but they made a deliberate choice to purposely include this subplot that wasn’t necessary.
I remember talking about how Arya’s time in Harrenhal was lightened so much in the show because in the books she suffered considerably more abuse. She was beaten very regularly and worked to the point of crawling to bed and bleeding hands. But then I realized recently, it may be because Maisie wasn’t old enough to have sexualized abuse at the time.
Yes, a character named Jeyne Poole had a similar arc in the books, but she was cut. Instead of cutting her disturbing plot, D&D went out of there way to have it with a barely legal actress and in so doing added more unnecessary sexual violence. And “so much worse”, okay, are we really comparing sexual assault and abuse stories now? Sansa was raped and that’s not okay just because it could be “so much worse”. One person’s considerable trauma does not negate another’s.
Sansa has a plot in the books. D&D took that from her so they could use her for this. This was a deliberate choice to value this plot, one of sexual violence and abuse, over a ton of other options Sansa as a character had. Moreover, a ton of other options D&D had for screentime.
Where’s Bran? Where’s Arianne? Where’s the Brotherhood Without Banners and Lady Stoneheart? Where’s the Greyjoy brothers? Where’s Young Griff, Duck, JonCon, and Septa Lemore? Hell, where’s Barristan Selmy?
It’s not that D&D came up with the idea of Ramsay torturing and raping on their own (though I would argue we’ve already seen plenty of his sadism already and more was gratuitous,) it’s that they valued this storyline over all the others. They went out of their way to include it and destroyed Sansa’s arc in the process. Meaning they chose this storyline over her old one and all the others they cut.
So, no, I don’t agree that D&D did the best they could. I think they did their best to include more sexualized violence.
Because really, what did this add? Why was it necessary to include over all the other plots? Sansa already had reason to hate the Boltons and Ramsay. Theon did, too. The audience didn’t need to be told Ramsay was a sadist and terrible, they already knew that. Sansa had already been abused and tormented before. How did this move the plot along?
Why was this so necessary that D&D bent over backwards to include it?
They even admitted they’ve been planning this since season 2. They didn’t just include it, they made sure it was included over everything else and seemed eager for it.