A tip for defending on Legendary, you need to jockey from a little bit further away than you can get away with on lower difficulty levels. And then only use the tackle button when you get a chance. In real life, attempting a tackle (of the FIFA 12 "stick out the leg variety") is a high risk move if your opponent is in good position to anticipate and take advantage. Luring in defenders to attempt a tackle is pretty much what all dribbling feints are for, and on Legendary, the AI actually dribbles with real life skill.
So the way to defend it is to give a little more space to contain, and then go in for tackles when things are in your favor. Such as when you can use the sideline as extra defender, or you have an actual extra defender, or after a cut back, or when their back is to you... In real life, most turnovers come from intercepting passes, or forcing turnovers off of pressing... not from direct stripping players from dribbling in the open field.
Closer to on topic... I've been tinkering with my own sliders, I've been using a lot of what is posted here as a reference, although I disagree with some people's general belief that the CPU needs to be toned down to have good Legendary sliders. Does anyone know of Legendary sliders that don't lessen the CPU side of things (or give the USER an advantage the CPU doesn't get)? I know that I'm in the minority in believing the CPU doesn't "cheat" on Legendary difficulty, and I'm sure that's why I've yet to see those types of sliders.
Thanks in advance.