You will get the separation with the two lines on the boards,and the board lines should easily outfish your flatlines.Not bad way if just starting out using boards or just have 2 boards.When we started trolling years ago we did the same with just a board off both sides and a line off both corners of the boat.But our flat lines were braided line with bottom bouncers and worm harnesses.Some days those flat lines did pretty well and others, nothing.You would be better to use a dipsy on those flat lines at a three setting.