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I think the only time he ever may have been really played was in that final episode. Looking at Stannis I think even with Melisandre out of the picture it wouldn't have changed anything except that finale. Stannis (is/was) probably the best tactician challenging for the throne and was clearly wanted the power so everything up to the finale he could have accomplished and done the same way without her. The only time he would have been played was in killing his daughter, which he was always against since he was really the only one besides Davos who cared for her.
After that, once he found his men deserted and wife killed herself I think he just wanted to die. Lets face it, anyone should have known how being outnumber like 3-1, plus them mounted on horseback, would end0