Mud Flaps again

After searching and reading all the posts about mud flaps I'm even more confused. What is the best way to protect a toad on a dolly behind a class A? Individual mud flaps behind the duals or a full width flap on the back of the coach? In each case, what is the optimal distance from the bottom of the flap to the pavement? Do the flaps need iron braces to prevent sailing or does that just cause problems on uneven roads when the tail end drops low? Is installing a guard on the front of the dolly the best solution? Thanks, Gary.