The longest leads go on outside board and shortest on inside board.I used to run the shallower lure on outside board.My thinking was the furthest lure from boat least likely to spook fish so thought best to run the shallower lure there.Problem was that you get more tangles.You can run shallowest and longest lead on outside board,but it would have to be a shallow running crank like a P10 there,

then a deeper running crank on other two lines.
I have been running a 2oz sinker on my inside boards,to match the depth of my outside boards and has worked really well.Ran the boards 80 on outside,70 middle and had a 20/20 and 20/25 lead with the sinker on inside boards.