It's not that the Others scheme a lot, -which they do-, it's like, always the same scheme, just more complex each and every time. "Ok, pretend you are on their side... but you're not... but pretend that you are, and when the time is right, reveal yourself as one of us and not one of them, because you were with us the whole time and not with them... ooooh the looks on their faces! We'll PUNK em good."
"...And then you will pretend after the reveal that you were REALLY with them and not REALLY with us, because you wanted to set us up, and then WE will act all shocked, because you are REALLY REALLY only with us and not really with them but you will only pretend that you are really with them. And then we will punk them for a second time. I can't believe they will fall for it twice, but they will!"