You should put the rack mounts against the fork, with the fender stays outboard. This is to minimize the bending moment on the screws by having the larger load closer to where the screw inserts. If this causes problems with your panniers you might consider using P-clamps on the fork blades for the fender stays instead of stacking them against the rack. You should be able to bend the fender stays to clear but if not the P-clamps will work fine.