Meh, I don't know. The problem with the books, and then going to the show in comparison, is that Martin all but beats you over the head with something, and the show is much more subtle. But Stannis in both seems to be more about the math. He litterally says somethign to the effect, in book 5, of:
"Would I trade 300 for 3000? Aye. But you'd best be true to your word."
He mentions a lot that Malisandra is equivalent to Aegon's Dragons. Or at least how he seems it. And when it appears she calls the shots, Stannis seems this as the way things play out with the Red God, not exactly her.
Here is an example of what I'm talking about
: (SPOLIERS)
Game of Thrones - Stannis Baratheon and Davos Seaworth ( Letter From Nights Watch HD) - YouTube
Overall though, where they take his character in the books will make it hard for them to portray him as completely ensorcelled. Unless they go
way off path.
And here's why I started loving the character in the first place: