I have a 30 inch custom vanity for our main floor vanity that is up against a wall. We are putting a quartz counter top on it with an under mount Kohler sink. The look we are going for is similar to the Restoration Hardware Martens Vanity but ours will be only 3 drawers as opposed to 6. The business that we are purchasing our quartz from suggested a backsplash on the back wall AS WELL as the side against the wall. It seems to me that it will look unbalanced. Any advice?