I agree with the former. But the latter is what I doubt. Littlefinger, Queen of Thorns, and even Varys, wield power without being leaders. |
But they're clever, and we have no evidence to suggest Sansa is, too. Sure, Petyr can train her in some of his cunning ways, but he can't train her to become smarter. He can only train her to use what is inside her to better effect.
All in all, I would be very disappointed with a plot that has her suddenly transforming into a power player.
Your forgetting, DsA, that Sansa is 13 by the last time we see her. She's been physically and emotionally abused, in a situation where she realised INSTANTLY she had no power to resist. Thats hardly a fair age or position to judge her intelligence or potential abilities at.
She's clearly learned to adapt in a way that suggests her mind is at least capable of intelligence. I also think your basing your opinion of her by comparing her to Arya. Which is an entirely unfair comparison, considering the differences in their basic personalities.
The Imp was correct above, when mentioning that Sansa wasn't raised to have a brain, she was raised to be a high lord's lady. And yet, also mentioned, was Catelyn. Like her or not, she was and incredibly smart woman, with a grasp of the complexities of the "Game" that far surpassed Ned's, and even Cercei's.
The Nature of all the Stark children is rooted in their upbringing and their intelligence (which we've seen All possess - well except perhaps Rickon, who may end up something of a wildchild).
Her transformation into a "power player" isn't going to be a sudden thing. Its going to be an ongoing theme of her POV due to what we've seen of "Allayne Stone's" POVs, and we've already seen her developing her skills - she's learned well enough to keep on Petyr's good side, by playing up her resemblance to her mother. She's well aware of the power her appearance has over him... its not going to debilitate Petyr completely, but he has little defence against it none-the-less.