you may have poor leverages for pulling and are ultimately screwed. when i pull conventional, in order to get my hips and be able to use them, my back is almost parallel to the floor. if i try to start like an oly lifter starts a jerk, i am so far behind the bar that my hips shoot first.
sumo is a bit better, however when the weights get heavier, my low back does most of the work. i think relatively long femurs in proportion to my other joints makes it so my hips are too far back in the correct starting position.